621 results on '"*COMPRESSION (Audiology)"'
Search Results
2. GEAR GUIDE.
- Subjects
FREQUENCY synthesizers ,SOUNDS ,COMPRESSION (Audiology) - Abstract
The article offers reviews of several synthesizers, including the Moog Mavis, Korg Volca Modular and PWM Malevolent, highlighting their features, build quality and versatility.
- Published
- 2023
3. Mechanical properties and strengthening mechanism of silty sands stabilized with steel slag-based geopolymer binder.
- Author
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Shengnian Wang, Zewei Chen, Zhijian Wu, Leilei Gu, Jun Su, and Zexuan Zhao
- Subjects
MECHANICAL properties of the heart ,SOLIDIFICATION ,COMPRESSION (Audiology) ,COMPRESSION loads - Abstract
Geopolymer binder has the advantages of early strength, fast solidification, high volume stability, and low permeability. It is beneficial to improve the mechanical performance of silty sands, saving cement consumption and being environmentally friendly. However, the strength improvement of silty sand stabilized with steel slag-based geopolymer was significantly controlled by their material composition and technical parameters. This study conducted a series of unconfined compression tests to investigate the material composition of steel slag-based geopolymer binders and their reasonable mixing ratio for silty sand stabilization. The optimum mixing ratio of precursor (steel slag) to alkaline activator (the combination of Na
2 SiO3 and CaO) and the optimum dosage of steel slag-based geopolymer for silty sand stabilization were explored. The strengthening mechanism of geopolymer-stabilized silty sands was discussed based on microstructural images and elemental concentrations of primary components observed by SEM and EDS. The results show that when the mass ratio of steel slag: Na2 SiO3 : CaO was 80:35:21, and the steel slag-based geopolymer material was 15%, the silty sand could achieve the best mechanical performance improvement. The microstructural characteristics of geopolymer-stabilized silty sands at different curing ages illustrated that the compactness and integrity of silty sand structures were enhanced over the curing age. The improving cementitious contact among particles and enlarging particle size was responsible for the strength improvement of silty sand. This research can provide a reference for applying steel slag-based geopolymer in silty sand stabilization in engineering practices. [ABSTRACT FROM AUTHOR]- Published
- 2023
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- View/download PDF
4. Study on crowd evacuation in subway transfer station fires based on numerical simulation.
- Author
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Feng Du, Qian Zhang, Kai Wang, Weilong Cui, Yangyang Guo, and Yun Deng
- Subjects
MECHANICAL properties of the heart ,SOLIDIFICATION ,COMPRESSION (Audiology) ,COMPRESSION loads - Abstract
In order to study the influencing factors of fire evacuation bottlenecks and evacuation time in subway transfer stations, a subway transfer station model was built using Pathfinder to simulate the emergency evacuation of passengers in a fire. Using the control variable method, the evacuation under different conditions is simulated by changing the parameters. The effects of the use of escalators, the speed of escalators, preference for stairs and escalators, the use of escalators, the familiarity of exits, the speed of personnel movement and the width of stairs on evacuation time are discussed and analyzed. The results show that the fire evacuation bottlenecks of subway transfer stations is each stair entrance. Evacuation time can be shortened by increasing the speed of escalators, increasing the proportion of escalator walkers, reducing the proportion of passengers who choose familiar exits to escape, increasing the speed of passengers and increasing the width of stairs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
5. Effectiveness of MP3 Coding Depends on the Music Genre: Evaluation Using Semantic Differential Scales.
- Author
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Papadakis, Nikolaos M., Aroni, Ioanna, and Stavroulakis, Georgios E.
- Subjects
SEMANTIC differential scale ,COMPRESSION (Audiology) ,MP3 (Audio coding standard) ,DISCRETE cosine transforms ,PSYCHOACOUSTICS - Abstract
MPEG-1 Layer 3 (MP3) is one of the most popular compression formats used for sound and especially for music. However, during the coding process, the MP3 algorithm negatively affects the spectral and dynamic characteristics of the audio file being compressed. The aim of this study is to evaluate the effect the MP3 coding format for different music genres and different bitrates via listening tests in which the original uncompressed files and the compressed files are compared. For this purpose, five different music genres were selected (rock, jazz, electronic, classical and solo instrument), and the files were compressed in three different bitrates (96 kbps, 160 kbps and 320 kbps). The semantic differential method was used, and ten bipolar scales were selected for the listening tests (e.g., better–worse, more distortion–less distortion, etc.). The following are the most important findings of this study: classical music was negatively affected the most among the genres due to the MP3 compression (lowest ratings in 8 out of 10 bipolar scales), the solo instrument was least affected among the genres (highest rating in 7 out of 10 bipolar scales), and for higher bit rates, the differences in ratings were small for all music genres. The findings of this study could be used to optimize and adapt the standard, depending on the music genre and the musical piece that needs to be encoded. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. GET MORE FROM YOUR DRIVE PEDALS.
- Subjects
EFFECTS pedals ,GUITAR tuning ,PEDAL point ,COMPRESSION (Audiology) ,INTERFERENCE (Sound) ,MUSIC industry ,MUSICAL instrument repair - Abstract
The article discusses various strategies for optimizing the use of drive pedals to achieve the best tube amp saturation, emphasizing the importance of experimenting with gain levels and pedal combinations. Topics include using a Tube Screamer for djent tones, managing gain stages effectively, and addressing common tone issues such as frequency conflicts and noise interference through isolated power supplies.
- Published
- 2023
7. An iterative forward analysis technique to determine the equation of state of dynamically compressed materials.
- Author
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Ali, S. J., Kraus, R. G., Fratanduono, D. E., Swift, D. C., and Eggert, J. H.
- Subjects
- *
EQUATIONS of state , *COMPRESSION (Audiology) , *HYDRODYNAMICS , *COMPUTER simulation , *LAGRANGIAN functions , *ITERATIVE methods (Mathematics) - Abstract
We developed an iterative forward analysis (IFA) technique with the ability to use hydrocode simulations as a fitting function for analysis of dynamic compression experiments. The IFA method optimizes over parameterized quantities in the hydrocode simulations, breaking the degeneracy of contributions to the measured material response. Velocity profiles from synthetic data generated using a hydrocode simulation are analyzed as a first-order validation of the technique. We also analyze multiple magnetically driven ramp compression experiments on copper and compare with more conventional techniques. Excellent agreement is obtained in both cases. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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8. Deformation patterns and hydrocarbon potential related to intracratonic strike-slip fault systems in the east of Central Uplift Belt in the Tarim Basin.
- Author
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Fei Ning, Jinbiao Yun, Zhongpei Zhang, and Peng Li
- Subjects
- *
FOSSIL fuels , *COMPRESSION (Audiology) , *PALEOZOIC Era , *DEEP learning , *GEOLOGY - Abstract
Strike-slip faults, proven to be closely linked to hydrocarbon migration and accumulation, are widespread in the Tarim Basin Craton. Deformation patterns in the eastern part of the Central Uplift Belt of the Tarim Basin are analyzed in detail to understand the deformation model and genetic mechanism of strike-slip faults, how their patterns impact reservoir formation and influence oil and gas potential. Regional tectonic events are taken into consideration to identify the primary factors that controlled the development of strike-slip faults in the region. The Tazhong Uplift in the eastern part of Central Uplift Belt is believed to be a complex anticlinal uplift formed by compression-and-torsion acting on the Cambrian e Middle Ordovician platform during the middleelate Caledonian period. Multi-stage development of this north-trending faultefold belt and the NE-trending strike-slip faults make it structurally complex. The NE-trending Paleozoic strike-slip faults were formed jointly by the differential thrusting of the Tazhong Uplift along Fault No. I and the NE-trending shear sliding of the basal fault blocks during the middleelate Caledonian e early Hercynian. Based on the distribution of effective source rocks, the tectonic setting during the period critical to hydrocarbon accumulation, and the distribution of conductive faults, the northern slope of the Tazhong Upliftd especially its west-central part where the NE-trending faults are developed is not only located close to the northern hydrocarbon source rock area but also possesses conditions suitable for the development of carbonate reservoirs. In addition, the NEtrending faults provide passage for initial development of the reservoir and the subsequent migration of oil and gas from the Aman area to the uplifted zone, making the Tazhong Uplift an extremely favorable area for oil and gas accumulation with substantial potential for exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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9. Amount of Frequency Compression in Bimodal Cochlear Implant Users Is a Poor Predictor for Audibility and Spatial Hearing.
- Author
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Sharma, Snandan, Nogueira, Waldo, van Opstal, A. John, Chalupper, Josef, Mens, Lucas H. M., and van Wanrooij, Marc M.
- Subjects
- *
RADIO frequency , *COMPRESSION (Audiology) , *COCHLEAR implants , *HEARING , *LISTENING comprehension , *ACOUSTIC localization , *SPEECH perception , *NOISE , *HEARING aid fitting , *HEARING levels , *ANALYSIS of variance , *MEDICAL equipment calibration , *PHYSIOLOGICAL adaptation , *DESCRIPTIVE statistics , *REPEATED measures design , *RESEARCH funding , *ALGORITHMS - Abstract
Purpose: Speech understanding in noise and horizontal sound localization is poor in most cochlear implant (CI) users with a hearing aid (bimodal stimulation). This study investigated the effect of static and less-extreme adaptive frequency compression in hearing aids on spatial hearing. By means of frequency compression, we aimed to restore high-frequency audibility, and thus improve sound localization and spatial speech recognition. Method: Sound-detection thresholds, sound localization, and spatial speech recognition were measured in eight bimodal CI users, with and without frequency compression. We tested two compression algorithms: a static algorithm, which compressed frequencies beyond the compression knee point (160 or 480 Hz), and an adaptive algorithm, which aimed to compress only consonants leaving vowels unaffected (adaptive knee-point frequencies from 736 to 2946 Hz). Results: Compression yielded a strong audibility benefit (high-frequency thresholds improved by 40 and 24 dB for static and adaptive compression, respectively), no meaningful improvement in localization performance (errors remained > 30 deg), and spatial speech recognition across all participants. Localization biases without compression (toward the hearing-aid and implant side for low- and high-frequency sounds, respectively) disappeared or reversed with compression. The audibility benefits provided to each bimodal user partially explained any individual improvements in localization performance; shifts in bias; and, for six out of eight participants, benefits in spatial speech recognition. Conclusions: We speculate that limiting factors such as a persistent hearing asymmetry and mismatch in spectral overlap prevent compression in bimodal users from improving sound localization. Therefore, the benefit in spatial release from masking by compression is likely due to a shift of attention to the ear with the better signal-to-noise ratio facilitated by compression, rather than an improved spatial selectivity. Supplemental Material: https://doi.org/10.23641/asha.16869485 [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. 'Modulation' by Richard Powers: Digital sound, compression and the short story.
- Author
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Hedges, Michael
- Subjects
SOUNDSCAPES (Auditory environment) ,SOUND in literature ,PHENOMENOLOGICAL aesthetics ,COMPRESSION (Audiology) ,SHORT story (Literary form) - Abstract
This article presents a reading of 'Modulation' (2008) by Richard Powers. Firstly, I consider the short story's representation of the MP3 music file, specifically its effects on how music is circulated and stored, as well as how it sounds. These changes are the result of different processes of compression. The MP3 format makes use of data compression to reduce the file size of a digital recording significantly. Such a loss of information devises new social and material relations between what remains of the original music, the recording industry from which MP3s emerged and the online markets into which they enter. I argue that 'Modulation' is a powerful evocation of a watershed moment in how we consume digital sound: what Jonathan Sterne has termed the rise of the MP3 as 'cultural artifact'. I contend that the short story, like the MP3, is also a compressed manner of representation. I use narrative theory and short story criticism to substantiate this claim, before positioning 'Modulation' alongside Powers's novels of information. I conclude by suggesting that 'Modulation' offers an alternative to representing information through an excess of data. This article reads Powers's compressed prose as a formal iteration of the data compression the story narrates. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
11. Compression for Clinicians: A Compass for Hearing Aid Fittings, Third Edition
- Author
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Theodore H. Venema and Theodore H. Venema
- Subjects
- Hearing aids--Design and construction, Hearing aids, Hearing aids--Fitting, Compression (Audiology)
- Abstract
Explaining the many developments that have taken place in the world of hearing aid compression, fitting methods, and real ear measurement, this text aims to make difficult concepts easier to understand and to explain in plain language many topics pertaining to compression. Directional microphones and digital features of noise reduction, feedback reduction, and expansion are also covered.
- Published
- 2017
12. Exonic UK AI Master.
- Subjects
DEBATE ,ARTIFICIAL intelligence ,MYSTERY ,COMPRESSION (Audiology) ,STEREO image - Abstract
The article presents the discussion on mastering being a process open to aural scrutiny and debate. Topics include AI Master is a new mastering plugin which hopes to take all of the mystery out of the mastering process; and dynamic range of the track through compression and limiting, spectral balancing, stereo image/soundstage alteration.
- Published
- 2023
13. Rayleigh wave interaction with surface-breaking cracks.
- Author
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Jian, X., Dixon, S., Guo, N., and Edwards, R.
- Subjects
- *
RAYLEIGH waves , *OSCILLATIONS , *COMPRESSION (Audiology) , *GEODYNAMICS , *ACOUSTIC surface waves - Abstract
This paper investigates Rayleigh wave interaction with simulated, surface breaking cracks using a finite element method, in which the scattered wave modes giving rise to the in-plane and out-of-plane displacements are presented. By looking at the contribution from all of the transmitted, reflected, and mode-converted signals at the crack, the magnitude of signal enhancement in the near field and the mechanism by which this occurs can be fully explained. Furthermore, oscillations in the Rayleigh wave reflection and transmission coefficients with crack depth in the far field can be explained by means of multiple reflected and transmitted wave modes at the crack, whose relative amplitudes are dependent on the crack depth. Results agree with previously published experimental measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
14. Temperature independent physisorption kinetics and adsorbate layer compression for Ar adsorbed on Pt(111).
- Author
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Kimmel, Greg A., Persson, Mats, Dohnálek, Z., and Kay, Bruce D.
- Subjects
- *
COMPRESSION (Audiology) , *MONOMOLECULAR films , *TEMPERATURE - Abstract
The influence of adlayer compression on the physisorption of Ar on Pt(111) is investigated using temperature programmed desorption and modulated molecular beams. We find that the difference in coverage between the compressed and uncompressed first layers is ∼10–15%. For coverages near one monolayer, this compression causes nearly temperature independent desorption kinetics over a wide temperature range (32–41 K). We present a theory that includes the effects of the compression on the desorption kinetics and explains the observed kinetics in terms of a competition between adsorbate–substrate and adsorbate–adsorbate interactions resulting in a continuous increase in the chemical potential near the completion of each successive layer. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
15. GET MORE FROM YOUR MULTI-EFFECTS.
- Author
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Sharma, Amit
- Subjects
COMPUTER software ,GUITAR amplifiers ,EFFECTS pedals ,ELECTRONIC musical instruments ,COMPRESSION (Audiology) - Abstract
The article discusses maximizing the potential of multi-effects units by utilizing computer software, ensuring uniform preset levels, and exploring various signal routing options. Topics include using the four-cable method for amp integration, pushing digital models to their limits, and combining analog pedals with multi-effects for a versatile setup.
- Published
- 2023
16. Bandwidth Extension of Speech Using Perceptual Criteria
- Author
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Visar Berisha, Steven Sandoval, Julie Liss, Visar Berisha, Steven Sandoval, and Julie Liss
- Subjects
- Speech perception, Compressed speech, Compression (Audiology), Psychoacoustics
- Abstract
Bandwidth extension of speech is used in the International Telecommunication Union G.729.1 standard in which the narrowband bitstream is combined with quantized high-band parameters. Although this system produces high-quality wideband speech, the additional bits used to represent the high band can be further reduced. In addition to the algorithm used in the G.729.1 standard, bandwidth extension methods based on spectrum prediction have also been proposed. Although these algorithms do not require additional bits, they perform poorly when the correlation between the low and the high band is weak. In this book, two wideband speech coding algorithms that rely on bandwidth extension are developed. The algorithms operate as wrappers around existing narrowband compression schemes. More specifically, in these algorithms, the low band is encoded using an existing toll-quality narrowband system, whereas the high band is generated using the proposed extension techniques. The first method relies only on transmitted high-band information to generate the wideband speech. The second algorithm uses a constrained minimum mean square error estimator that combines transmitted high-band envelope information with a predictive scheme driven by narrowband features. Both algorithms make use of novel perceptual models based on loudness that determine optimum quantization strategies for wideband recovery and synthesis. Objective and subjective evaluations reveal that the proposed system performs at a lower average bit rate while improving speech quality when compared to other similar algorithms.
- Published
- 2013
17. Relationship between myocardial bridge compression severity and haemodynamic perturbations.
- Author
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Javadzadegan, Ashkan, Moshfegh, Abouzar, and Hassanzadeh Afrouzi, Hamid
- Subjects
- *
MYOCARDIAL infarction , *COMPRESSION (Audiology) , *ANGIOGRAPHY , *INTRAVASCULAR ultrasonography , *PATIENTS , *COMPUTATIONAL fluid dynamics , *SHEARING force - Abstract
Objectives: This study aims to examine the alteration in coronary haemodynamics with increasing the severity of vessel compression caused by myocardial bridging (MB). Methods: Angiography and intravascular ultrasound were performed in 10 patients with MB with varying severities of systolic compression in the left anterior descending (LAD) artery. Computer models of MB were developed and transient computational fluid dynamics simulations were performed to derive distribution of blood residence time and shear stress. Results: With increasing the severity of bridge compression, a decreasing trend was observed in the shear stress over proximal segment whereas an increasing trend was found in the shear stress over bridge segment. When patients were divided into 2 groups based on the average systolic vessel compression in the whole cohort (%CRave = 27.38), patients with bridges with major systolic compression (>%CRave) had smaller shear stress and higher residence time in the proximal segment compared to those with bridges with minor systolic compression (<%CRave) (0.37 ± 0.23 vs 0.69 ± 0.29 Pa and 0.0037 ± 0.0069 vs 0.022 ± 0.0094 s). In contrast, patients with bridges with major systolic compression had greater shear stress in the bridge segment compared to those with bridges with minor systolic compression (2.49 ± 2.06 vs 1.13 ± 0.89 Pa). No significant difference was found in the distal shear stress of patients with bridges with major and minor systolic compression. Conclusion: Our findings revealed a direct relationship between the severity of systolic compression of MB and haemodynamic perturbations in the proximal segment such that the increased systolic vessel compression was associated with decreased shear stress and increased blood residence time. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
18. Analysis of flow stress and microstructure during hot compression of 6099 aluminum alloy (AA6099).
- Author
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Chamanfar, Ahmad, Alamoudi, Mohammed T., Nanninga, Nicholas E., and Misiolek, Wojciech Z.
- Subjects
- *
ALUMINUM alloys , *COMPRESSION (Audiology) , *COMPRESSION loads , *METAL microstructure , *STRAINS & stresses (Mechanics) - Abstract
Abstract The hot deformation behavior of a newly developed AA6099 alloy was investigated after homogenization. To this end, Gleeble® isothermal hot compression tests were performed at temperatures of 350, 400, 450, and 500 °C, and strain rates of 0.01, 0.1, and 1 s−1 up to a true strain of 0.8. The dependency of the flow stress on the deformation temperature, strain, and strain rate was analyzed. In addition, the constitutive equations relating the flow stress to the deformation temperature and strain rate were derived using a power-law empirical model. Also, the microstructures and dynamic softening mechanisms of the alloy under various deformation conditions were examined using light optical microscopy (LOM) and electron back scattered diffraction (EBSD) techniques. The correlation between the flow behavior, different microstructures, and dynamic softening mechanisms at various hot compression conditions was determined. The kinetic analysis and microstructural evolution indicated that the main flow softening mechanism for homogenized AA6099 was dynamic recovery (DRV). Partial dynamic recrystallization (DRX) enhanced the flow softening especially at low deformation temperatures and high strain rates, i.e., at high Zener-Hollomon parameter (Z) values. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Prosodic encoding of focus in Hijazi Arabic.
- Author
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Alzaidi, Muhammad Swaileh, Xu, Yi, and Xu, Anqi
- Subjects
- *
ACOUSTICS , *VOCABULARY , *COMPRESSION (Audiology) , *VERSIFICATION ,ARABIC dialects - Abstract
Highlights • We present findings of the first systematic acoustic analysis of focus in Hijazi Arabic (HA), an under-researched Arabic dialect. • Focused words have significantly expanded excursion size, higher maximum F0 and longer duration. Post-focus words have significantly lowered F0 (except in the case of penultimate focus). Pre-focus words, in contrast, lack systematic changes. • These patterns are consistent with previously reported prosodic patterns of focus in other Arabic dialects. • Arabic appears to belong to a group of languages that all exhibit post-focus compression (PFC), as opposed to languages that lack PFC. • The results also show evidence of prosodic differences between contrastive focus and information focus. But the difference is unlikely to be categorical. Abstract This paper presents findings of the first systematic acoustic analysis of focus prosody in Hijazi Arabic (HA), an under-researched Arabic dialect. A question-answer paradigm was used to elicit information and contrastive focus at different sentence locations in comparison with their neutral focus counterparts. Systematic acoustic analyses were performed to compare all the focus conditions, in terms of both continuous F 0 trajectories and specific acoustic measurements. Results show that focused words have significantly expanded excursion size, higher maximum F 0 and longer duration. Post-focus words have significantly lowered F 0 (except in the case of penultimate focus). Pre-focus words, in contrast, lack systematic changes. These patterns are consistent with previously reported prosodic patterns of focus in other Arabic dialects. They are also consistent with a number of others languages that have also been applied similar systematic acoustic analyses. Thus Arabic appears to belong to a group of languages that all exhibit post-focus compression (PFC), as opposed to languages that lack PFC. In addition, the results also show evidence of prosodic differences between contrastive focus and information focus. This difference, however, is interpreted as due to a methodological feature that allowed elicitation of incredulity related to contrastive focus, rather than as a language-specific property. It is also argued that the possible involvement of incredulity in focus marking needs further research. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
20. Flexible representation and manipulation of audio signals on quantum computers.
- Author
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Yan, Fei, Iliyasu, Abdullah M., Guo, Yiming, and Yang, Huamin
- Subjects
- *
QUANTUM computers , *MATRIX inversion , *QUANTUM computing , *AMPLITUDE estimation , *COMPRESSION (Audiology) - Abstract
Abstract By analyzing the numerical representation of amplitude values in audio signals and integrating the time component, a representation for audio signals on quantum computers, FRQA, is proposed. The FRQA representation is a normalized state that facilitates basic audio signal operations targeting the amplitude and time parameters. The preparation and retrieval for FRQA are discussed and based on the resulting state, we realize the circuits to accomplish basic audio signal operations such as signal addition, signal inversion, signal delay, and signal reversal. In future, these operations can be employed as the major components to build advanced operations for specific applications as well as facilitate secure transmission of audio content in the quantum computing domain. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
21. Mechanism of bone-conducted hearing: mathematical approach.
- Author
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Chan, Wei Xuan, Yoon, Yong-Jin, and Kim, Namkeun
- Subjects
- *
BONE conduction , *WKB approximation , *MATHEMATICAL models , *COMPRESSION (Audiology) , *SIMULATION methods & models - Abstract
For better understanding of bone-conducted (BC) hearing, a mechanical BC model is formulated using the Wentzel-Kramers-Brillouin (WKB) method. The BC hearing can be generally described by three main mechanisms: (1) cochlear fluid inertia, (2) in-phase motion of the outer bony shell, and (3) out-of-phase motion of the outer bony shell. Specifically, the second and third mechanisms can be identically explained by symmetric pressure compression-expansion and anti-symmetric compression-expansion, respectively. In this study, simulation results show that both the symmetric and anti-symmetric compression-expansion modes become significant at frequencies above 7 kHz while the fluid inertial mode is dominant at lower frequencies. The density difference between the scala fluid and soft cells of basilar membrane and the amplitude of the anti-symmetric compression-expansion input are identified as the difference between the air conduction and bone conduction. The natural frequency of the cochlear duct wall determines the magnitudes between the three mechanism and is approximated to be in the order of 10 MHz and above. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
22. Efficient characterization of individual differences in compression ratio preference.
- Author
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Baltzell, Lucas S, Xia, Jing, and Kalluri, Sridhar
- Subjects
- *
COMPRESSION (Audiology) , *HEARING aids , *ACOUSTOELECTRIC devices , *BAYESIAN analysis , *LISTENING , *AUDIOGRAM - Abstract
While wide dynamic range compression (WDRC) is a standard feature of modern hearing aids, it can be difficult to fit compression settings to individual hearing aid users. The goal of the current study was to develop a practical test to learn the preference of individual listeners for different compression ratio (CR) settings in different listening conditions (speech-in-quiet and speech-in-noise). While it is possible to exhaustively test different CR settings, such methods can take many hours to complete, making them impractical. Bayesian optimization methods were used to find CR preferences in individual listeners in a relatively short amount of time. Using this practical preference learning test, individual differences in CR preference were examined across a relatively wide range of CR settings in different listening conditions. In experiment 1, the accuracy of the preference learning test in normal hearing listeners was verified. In experiment 2, it is shown that individual hearing impaired listeners differ in their CR preferences, and listeners tended to prefer the CR setting identified by the preference learning test over both linear gain or the National Acoustics Lab--Nonlinear 2 CR prescription based on their audiograms. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
23. Invited Article: Optical dynamic range compression.
- Author
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Jiang, Yunshan, Zhao, Saili, and Jalali, Bahram
- Subjects
SIGNAL-to-noise ratio ,DISTRIBUTION (Probability theory) ,OPTICAL radar ,COMPRESSION (Audiology) ,ANALOG-to-digital converters ,PHOTOVOLTAIC effect - Abstract
We introduce the concept of optical dynamic range compression and discuss its utilities in the non-uniform quantization, enhancing the signal-to-noise ratio as well as reshaping signal's statistical distribution and extending the detection range in light detection and ranging systems. The technology represents a photonics hardware accelerator that reduces the burden on the dynamic range of the photodetection and the data acquisition including the required number of bits of the analog-to-digital converter. The energy of photons that are intentionally blocked can be harvested using a two-photon photovoltaic effect. Implementations using other approaches are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
24. Quick effect tips: Part 5.
- Subjects
PRODUCTION music ,COMPRESSION (Audiology) ,MUSICAL pitch ,SOUNDS ,JAZZ vocals - Abstract
The article focuses on quick and simple effect tips for audio processing. It suggests using saturation instead of compression to reduce a signal's peak level while increasing its average level, achieving perceived volume without hitting higher levels in your DAW. Additionally, it recommends applying flanging to metallic sounds, using distortion on polyphonic material with controlled pitch relationships and incorporating reverb on delays for vocal treatments.
- Published
- 2023
25. UNDERSTANDING: Transient shaping.
- Subjects
AUDIO amplifiers ,PRODUCTION music ,MUSICAL instruments ,SOUNDS ,COMPRESSION (Audiology) - Abstract
The article focuses on the importance of transient shaping in audio production, explaining that transients are the short, sharp spikes at the start of waveforms responsible for a sound's initial impact. It discusses three approaches to shaping transients: transient designer plugins, compression/limiting and saturation.
- Published
- 2023
26. On Achievability for Downlink Cloud Radio Access Networks With Base Station Cooperation.
- Author
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Wang, Chien-Yi, Wigger, Michele, and Zaidi, Abdellatif
- Subjects
- *
CLOUD computing , *RADIO access networks , *RADIO networks , *RADIO broadcasting , *COMPRESSION (Audiology) , *GAUSSIAN measures , *INFORMATION sharing - Abstract
This paper investigates the downlink of a cloud radio access network (C-RAN) in which a central processor communicates with two mobile users through two base stations (BSs). The BSs act as relay nodes and cooperate with each other through error-free rate-limited links. We develop and analyze two coding schemes for this scenario. The first coding scheme modifies the Liu–Kang scheme (to make it amenable to a rigorous analysis) and extends it to introduce common codewords and to apply for downlink C-RAN with BS-to-BS cooperation. This first coding scheme enables arbitrary correlation among the auxiliary codewords that are recovered by the BSs. We show that this scheme improves over previous schemes for various instances of Gaussian C-RAN channels. In particular, in many scenarios, the scheme can better exploit the possibility of BS-to-BS cooperation than other schemes. The second coding scheme extends the distributed decode and forward (DDF) scheme by means of Gray–Wyner compression and by exploiting the cooperation links between BSs. In addition and as a separate extension, we provide an improved capacity approximation for the DDF strategy for the capacity of a general $N$ -BS $L$ -user C-RAN model in the memoryless Gaussian case. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
27. Representational momentum in dynamic facial expressions is modulated by the level of expressed pain: Amplitude and direction effects.
- Author
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Prigent, Elise, Amorim, Michel-Ange, and de Oliveira, Armando Mónica
- Subjects
- *
FACE perception , *IMPLICIT memory , *COMPRESSION (Audiology) , *VISUAL perception , *FACIAL expression - Abstract
Humans have developed a specific capacity to rapidly perceive and anticipate other people's facial expressions so as to get an immediate impression of their emotional state of mind. We carried out two experiments to examine the perceptual and memory dynamics of facial expressions of pain. In the first experiment, we investigated how people estimate other people's levels of pain based on the perception of various dynamic facial expressions; these differ both in terms of the amount and intensity of activated action units. A second experiment used a representational momentum (RM) paradigm to study the emotional anticipation (memory bias) elicited by the same facial expressions of pain studied in Experiment 1. Our results highlighted the relationship between the level of perceived pain (in Experiment 1) and the direction and magnitude of memory bias (in Experiment 2): When perceived pain increases, the memory bias tends to be reduced (if positive) and ultimately becomes negative. Dynamic facial expressions of pain may reenact an 'immediate perceptual history' in the perceiver before leading to an emotional anticipation of the agent's upcoming state. Thus, a subtle facial expression of pain (i.e., a low contraction around the eyes) that leads to a significant positive anticipation can be considered an adaptive process-one through which we can swiftly and involuntarily detect other people's pain. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. Swept-tone stimulus-frequency otoacoustic emissions: Normative data and methodological considerations.
- Author
-
Abdala, Carolina, Guardia, Yeini C., and Shera, Christopher A.
- Subjects
- *
OTOACOUSTIC emissions , *AUDIO frequency , *ACOUSTIC stimulation , *SOUND pressure measurement , *FREQUENCY multipliers , *COCHLEA , *RESPONSE inhibition , *COMPRESSION (Audiology) - Abstract
Stimulus-frequency otoacoustic emissions (SFOAEs) are reflection-source emissions, and are the least familiar and perhaps most underutilized otoacoustic emission. Here, normative SFOAE data are presented from a large group of 48 young adults at probe levels from 20 to 60 dB sound pressure level (SPL) across a four-octave frequency range to characterize the typical SFOAE and describe recent methodological advances that have made its measurement more efficient. In young-adult ears, SFOAE levels peaked in the low-to-mid frequencies at mean levels of ∼6–7 dB SPL while signal-to-noise ranged from 23 to 34 dB SPL and test-retest reliability was ±4 dB for 90% of the SFOAE data. On average, females had ∼2.5 dB higher SFOAE levels than males. SFOAE input/output functions showed near linear growth at low levels and a compression threshold averaging 35 dB SPL across frequency. SFOAE phase accumulated ∼32–36 cycles across four octaves on average, and showed level effects when converted to group delay: low-level probes produced longer SFOAE delays. A “break” in the normalized SFOAE delay was observed at 1.1 kHz on average, elucidating the location of the putative apical-basal transition. Technical innovations such as the concurrent sweeping of multiple frequency segments,
post hoc suppressor decontamination, and apost hoc artifact-rejection technique were tested. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
29. Fixing Flawed Audio in Adobe Creative Cloud.
- Author
-
Ozer, Jan
- Subjects
SOUND recording & reproducing software ,ADOBE software ,SOFTWARE as a service ,NOISE control ,COMPRESSION (Audiology) - Abstract
The article discusses the procedure of correcting and improving flawed audio clips using the upgraded Premiere Pro CC 2019 creative audio correcting cloud software of software company Adobe. It outlines details on the various tools and features of the software and discusses the process steps which involves removal of transient noise, audition noise reduction and audio compression.
- Published
- 2019
30. Viewing an ultra-brief chest compression only video improves some measures of bystander CPR performance and responsiveness at a mass gathering event.
- Author
-
Beskind, Daniel L., Stolz, Uwe, Thiede, Rebecca, Hoyer, Riley, Robertson, Whitney, Brown, Jeffrey, Ludgate, Melissa, Tiutan, Timothy, Shane, Romy, McMorrow, Deven, Pleasants, Michael, Kern, Karl B., and Panchal, Ashish R.
- Subjects
- *
COMPRESSION (Audiology) , *CARDIOPULMONARY resuscitation , *CARDIAC arrest , *THERAPEUTICS , *CARDIAC resuscitation , *CARDIAC massage , *HUMAN anatomical models , *LONGITUDINAL method , *POPULATION density , *TIME , *UNIVERSITIES & colleges , *VIDEO recording , *LOGISTIC regression analysis , *BLIND experiment ,HEALTH of patients - Abstract
Background: CPR training at mass gathering events is an important part of health initiatives to improve cardiac arrest survival. However, it is unclear whether training lay bystanders using an ultra-brief video at a mass gathering event improves CPR quality and responsiveness.Objective: To determine if showing a chest-compression only (CCO) Ultra-Brief Video (UBV) at a mass gathering event is effective in teaching lay bystanders CCO-CPR.Methods: Prospective control trial in adults (age >18) who attended either a women's University of Arizona or a men's Phoenix Suns basketball game. Participants were evaluated using a standardized cardiac arrest scenario with Laerdal Skillreporter™ mannequins. CPR responsiveness (calling 911, time to calling 911, starting compressions within two minutes) and quality (compression rate, depth, hands-off time) were assessed for participants and data collected at Baseline and Post-intervention. Different participants were tested before and after the exposure of the UBV. Data were analyzed via the intention to treat principle using logistic regression for binary outcomes and median regression for continuous outcomes, controlling for clustering by venue.Results: A total of 96 people were consented (Baseline=45; Post intervention=51). CPR responsiveness post intervention improved with faster time to calling 911 (s) and time to starting compressions (sec). Likewise, CPR quality improved with deeper compressions and improved hands-off time.Conclusions: Showing a UBV at a mass gathering sporting event is associated with improved CPR responsiveness and performance for lay bystanders. This data provides further support for the use of mass media interventions. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
31. The Detection of Phase Amplitude Coupling during Sensory Processing.
- Author
-
Seymour, Robert A., Rippon, Gina, and Kessler, Klaus
- Subjects
OSCILLATIONS ,SENSORIMOTOR integration ,COMPRESSION (Audiology) - Abstract
There is increasing interest in understanding how the phase and amplitude of distinct neural oscillations might interact to support dynamic communication within the brain. In particular, previous work has demonstrated a coupling between the phase of low frequency oscillations and the amplitude (or power) of high frequency oscillations during certain tasks, termed phase amplitude coupling (PAC). For instance, during visual processing in humans, PAC has been reliably observed between ongoing alpha (8-13 Hz) and gamma-band (>40 Hz) activity. However, the application of PAC metrics to electrophysiological data can be challenging due to numerous methodological issues and lack of coherent approaches within the field. Therefore, in this article we outline the various analysis steps involved in detecting PAC, using an openly available MEG dataset from 16 participants performing an interactive visual task. Firstly, we localized gamma and alpha-band power using the Fieldtrip toolbox and extracted time courses from area V1, defined using a multimodal parcelation scheme. These V1 responses were analyzed for changes in alpha-gamma PAC, using four common algorithms. Results showed an increase in alpha (7-13 Hz)-gamma (40-100 Hz) PAC in response to the visual grating stimulus, though specific patterns of coupling were somewhat dependent upon the algorithm employed. Additionally, post-hoc analyses showed that these results were not driven by the presence of non-sinusoidal oscillations and that trial length was sufficient to obtain reliable PAC estimates. Finally, throughout the article, methodological issues and practical guidelines for ongoing PAC research will be discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
32. Acoustic and perceptual effects of amplitude and frequency compression on high-frequency speech.
- Author
-
Alexander, Joshua M. and Rallapalli, Varsha
- Subjects
- *
COMPRESSION (Audiology) , *AUDIO frequency , *FRICATIVES (Phonetics) , *PHONEME (Linguistics) , *WAVE amplification - Abstract
This study investigated how six different amplification methods influence acoustic properties, and subsequently perception, of high-frequency cues in fricatives that have been processed with conventional full bandwidth amplification or nonlinear frequency compression (NFC)--12 conditions total. Amplification methods included linear gain, fast/slow-acting wide dynamic range compression crossed with fixed/individualized compression parameters, and a method with adaptive time constants. Twenty-one hearing-impaired listeners identified seven fricatives in nonsense syllables produced by female talkers. For NFC stimuli, frequency-compressed filters that precisely aligned 1/3-octave bands between input and output were used to quantify effective compression ratio, audibility, and temporal envelope modulation relative to the input. Results indicated significant relationships between these acoustic properties, each of which contributed significantly to fricative recognition across the entire corpus of stimuli. Recognition was significantly better for NFC stimuli compared with full bandwidth stimuli, regardless of the amplification method, which had complementary effects on audibility and envelope modulation. Furthermore, while there were significant differences in recognition across the amplification methods, they were not consistent across phonemes. Therefore, neither recognition nor acoustic data overwhelmingly suggest that one amplification method should be used over another for transmission of high-frequency cues in isolated syllables. Longer duration stimuli and more realistic listening conditions should be examined. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
33. Rippling pattern of distortion product otoacoustic emissions evoked by high-frequency primaries in guinea pigs.
- Author
-
Burwood, George W. S., Russell, Ian J., and Lukashkin, Andrei N.
- Subjects
- *
OTOACOUSTIC emissions , *PHASE oscillations , *MAXIMA & minima , *COMPRESSION (Audiology) , *BASILAR membrane - Abstract
The origin of ripples in distortion product otoacoustic emission (DPOAE) amplitude which appear at specific DPOAE frequencies during f1 tone sweeps using fixed high frequency f2 (>20 kHz) in guinea pigs is investigated. The peaks of the ripples, or local DPOAE amplitude maxima, are separated by approximately half octave intervals and are accompanied by phase oscillations. The local maxima appear at the same frequencies in DPOAEs of different order and velocity responses of the stapes and do not shift with increasing levels of the primaries. A suppressor tone had little effect on the frequencies of the maxima, but partially suppressed DPOAE amplitude when it was placed close to the f2 frequencies. These findings agree with earlier observations that the maxima occur at the same DPOAE frequencies, which are independent of the f2 and the primary ratio, and thus are likely to be associated with DPOAE propagation mechanisms. Furthermore, the separation of the local maxima by approximately half an octave may suggest that the maxima are due to interference of the travelling waves along the basilar membrane at the frequency of the DPOAE. It is suggested that the rippling pattern appears because of interaction between DPOAE reverse travelling waves with standing waves formed in the cochlea. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
34. Effects of reverberation, background talker number, and compression release time on signal-to-noise ratio.
- Author
-
Reinhart, Paul, Zahorik, Pavel, and Souza, Pamela E.
- Subjects
- *
SPEECH perception , *SIGNAL-to-noise ratio , *COMPRESSION (Audiology) , *DYNAMIC range (Acoustics) , *SOUND reverberation , *HEARING aids - Abstract
Wide dynamic range compression (WDRC) processing in hearing aids alters the signal-to-noise ratio (SNR) of a speech-in-noise signal. This effect depends on the modulations of the speech and noise, input SNR, and WDRC speed. The purpose of the present experiment was to examine the change in output SNR caused by the interaction between modulation characteristics and WDRC speed. Two modulation manipulations were examined: (1) reverberation and (2) variation in background talker number. Results indicated that fast-acting WDRC altered SNR more than slow-acting WDRC; however, reverberation reduced this difference. Additionally, less modulated maskers led to poorer output SNRs than modulated maskers. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
35. Compression test and analysis of multi-limbs built-up cold-formed steel stub columns.
- Author
-
Liao, Fangfang, Wu, Hanheng, Wang, Ruizhi, and Zhou, Tianhua
- Subjects
- *
TUBULAR steel structures , *FINITE element method , *MECHANICAL buckling , *COMPRESSION (Audiology) , *COMPRESSION loads - Abstract
Multi-limbs built-up cold-formed steel stub column is a main structural member consisting of a single C-shaped and U-shaped basic component connected by self-drilling screws. Axial compression bearing capacity tests and finite element analysis of nine multi-limbs built–up cold–formed steel stub columns with three different section forms were conducted in this paper. The results of finite element analysis are close to the test results, which verify the accuracy of the finite element analysis. In order to study the influence of width–thickness ratio and screw spacing on the bearing capacity of the build-up column, the parametric analysis was carried out on the maximum width–thickness ratio of the plates and the screw spacing. The results show that the failure modes of all specimens are local buckling and distortional buckling. Multi-limbs built–up cold–formed steel stub columns consisting of a few basic components can work in harmony, the integral behavior is desirable. The axial load bearing capacity of the multi-limbs built-up section stub column increases when the maximum width–thickness ratio of the plates decreases; the screw spacing has a little impact on the ultimate axial compressive capacity and the buckling capacity of the multi-limbs built-up cold-formed steel stub columns. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. A mixture approach to the acoustic properties of a macroscopically inhomogeneous porous aluminum in the equivalent fluid approximation.
- Author
-
Sacristan, C. J., Dupont, T., Sicot, O., Leclaire, P., Verdière, K., Panneton, R., and Gong, X. L.
- Subjects
- *
ALUMINUM foam , *ACOUSTICS , *MELAMINE , *COMPRESSION (Audiology) , *SIMULATED annealing , *MATHEMATICAL optimization - Abstract
The acoustic properties of an air-saturated macroscopically inhomogeneous aluminum foam in the equivalent fluid approximation are studied. A reference sample built by forcing a highly compressible melamine foam with conical shape inside a constant diameter rigid tube is studied first. In this process, a radial compression varying with depth is applied. With the help of an assumption on the compressed pore geometry, properties of the reference sample can be modelled everywhere in the thickness and it is possible to use the classical transfer matrix method as theoretical reference. In the mixture approach, the material is viewed as a mixture of two known materials placed in a patchwork configuration and with proportions of each varying with depth. The properties are derived from the use of a mixing law. For the reference sample, the classical transfer matrix method is used to validate the experimental results. These results are used to validate the mixture approach. The mixture approach is then used to characterize a porous aluminium for which only the properties of the external faces are known. A porosity profile is needed and is obtained from the simulated annealing optimization process. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
37. Evaluation of a method for enhancing interaural level differences at low frequencies.
- Author
-
Moore, Brian C. J., Kolarik, Andrew, Stone, Michael A., and Young-Woo Lee
- Subjects
- *
BINAURAL audio , *BINAURAL hearing aids , *COMPRESSION (Audiology) , *HEARING aid design & construction , *HEARING aid fitting - Abstract
A method (called binaural enhancement) for enhancing interaural level differences at low frequencies, based on estimates of interaural time differences, was developed and evaluated. Five conditions were compared, all using simulated hearing-aid processing: (1) Linear amplification with frequency-response shaping; (2) binaural enhancement combined with linear amplification and frequency-response shaping; (3) slow-acting four-channel amplitude compression with independent compression at the two ears (AGC4CH); (4) binaural enhancement combined with four-channel compression (BE-AGC4CH); and (5) four-channel compression but with the compression gains synchronized across ears. Ten hearing-impaired listeners were tested, and gains and compression ratios for each listener were set to match targets prescribed by the CAM2 fitting method. Stimuli were presented via headphones, using virtualization methods to simulate listening in a moderately reverberant room. The intelligibility of speech at ± 60° azimuth in the presence of competing speech on the opposite side of the head at ± 60° azimuth was not affected by the binaural enhancement processing. Sound localization was significantly better for condition BE-AGC4CH than for condition AGC4CH for a sentence, but not for broadband noise, lowpass noise, or lowpass amplitude-modulated noise. The results suggest that the binaural enhancement processing can improve localization for sounds with distinct envelope fluctuations. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
38. The role of compression in the simultaneous masker phase effect.
- Author
-
Tabuchi, Hisaaki, Laback, Bernhard, Necciari, Thibaud, and Majdak, Piotr
- Subjects
- *
COMPRESSION (Audiology) , *AUDITORY masking , *HARMONIC suppression filters , *BANDWIDTHS , *HAIR cells - Abstract
Peripheral compression is believed to play a major role in the masker phase effect (MPE). While compression is almost instantaneous, activation of the efferent system reduces compression in a temporally evolving manner. To study the role of efferent-controlled compression in the MPE, in experiment 1, simultaneous masking of a 30-ms 4-kHz tone by 40-ms Schroeder-phase harmonic complexes was measured with on- and off-frequency precursors as a function of masker phase curvature for two masker levels (60 and 90 dB sound pressure level). The MPE was quantified by the threshold range [min/max difference (MMD)] across the phase curvatures. For the 60-dB condition, the presence of on-frequency precursor decreased the MMD from 10 to 5 dB. Experiment 2 studied the role of the precursor on the auditory filter's bandwidth. The on-frequency precursor was found to increase the bandwidth, an effect incorporated in the subsequent modeling. A model of the auditory periphery including cochlear filtering and basilar membrane compression generally underestimated the MMDs. A model based on two-step compression, including compression of inner hair cells, accounted for the MMDs across precursor and level conditions. Overall, the observed precursor effects and the model predictions suggest an important role of compression in the simultaneous MPE. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. An efficient algorithm for double compressed AAC audio detection.
- Author
-
Jin, Chao, Wang, Rangding, Yan, Diqun, Ma, Pengfei, and Zhou, Jinglei
- Subjects
ALGORITHM research ,COMPRESSION (Audiology) ,MARKOV processes ,HUFFMAN codes ,PROBABILITY measures - Abstract
As a new generation of compression encoding standard, MPEG-2/4 Advanced Audio Coding (AAC) would be a widely-used audio format in the near future. However, these AAC audios often be forged by audio forgers for their own benefits in some significant events, which will cause double AAC compression. In this paper, the probability values and Markov features based on the Huffman codebook indexes of AAC audio were constructed and an efficient algorithm is proposed to detect double compression. Experimental results demonstrate that our method has high detection accuracy and low computational complexity. To the best of our knowledge, it is the first time to apply double compression detection to AAC audio forensics. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
40. Investigation of compression ratio and fuel effect on combustion and PM emissions in a DISI engine.
- Author
-
Lattimore, Thomas, Herreros, José M., Xu, Hongming, and Shuai, Shijin
- Subjects
- *
COMPRESSION (Audiology) , *COMPRESSION loads , *COMBUSTION , *OXYGENATION (Chemistry) , *SPARK ignition engines ,ENVIRONMENTAL aspects ,PARTICULATE matter & the environment - Abstract
Oxygenated fuel components such as the alcohols of 1-butanol and ethanol are well-known for their potential to improve engine combustion and PM emissions, and these particular fuels are receiving ever greater attention due to their renewable nature giving them great CO 2 emission reduction potential. This paper investigates the effect of compression ratio and fuel properties on combustion, gaseous emissions and PM emissions of an experimental single-cylinder direct injection spark ignition (DISI) engine. The tests were carried out at an engine load of 8.5 bar, at various compression ratios between 10.7 and 11.5, with Bu20 (20%vol 1-butanol in gasoline) and E20 (20%vol ethanol in gasoline) fuel blends along with a reference fuel of gasoline. The results show that 1-butanol and ethanol addition to gasoline is effective to advance the MFB50 point and shorten the combustion duration. 1-butanol addition to gasoline is effective to reduce PM number emissions, while NO x reduction is the main benefit of ethanol addition. It is concluded that synergies between compression ratio and alcohol addition to gasoline enable to simultaneously control gaseous and particulate matter emissions while improving fuel economy with respect to standard gasoline combustion. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
41. Too fast to be true? Exploring time compression in simultaneous interpreting.
- Author
-
Barranco-Droege, Rafael
- Subjects
- *
SIMULTANEOUS interpreting , *COMPRESSION (Audiology) , *COMPRESSED speech , *SPEECH perception , *LINGUISTICS - Abstract
When speaking fast, we tend to reduce sentence-ending pauses, potentially impinging on their function as cues for the listener. Earlier research indicates that fast natural speech is harder to process than time-compressed speech, in which all pauses are reduced proportionally. To check whether this advantage for listening withstands the high cognitive demands of simultaneous interpreting, we set up an experiment using two videotaped versions of a content-rich speech. One was delivered by the speaker at 166 words/min and the other one was an originally slower presentation made similarly fast using a 20% compression rate. We asked eight professional practitioners to interpret both versions and to estimate their interpreting difficulty in terms of several dimensions. When the two versions were presented separately, the subjects perceived the time-compressed recording as harder to interpret with regard to linguistic expression . When comparing them, they perceived the time-compressed version either as similarly or as more difficult to interpret than the fast natural version. These results cast doubts on the conjectured advantage of time compression for the interpretation of content-rich speeches. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
42. Experimental and Numerical Investigation on Thin-Walled Single and Starred Angle Sections Under Compression.
- Author
-
Beulah Gnana Ananthi, G., Vishuvardhan, S., and Samuel Knight, G.
- Subjects
- *
ANGLE sections (Structural engineering) , *COMPRESSION (Audiology) , *COLUMN chromatography - Abstract
This paper presents experimental and numerical investigations on the behaviour of thin-walled cold-formed steel single and starred angles with lips as stub and short columns, subjected to axial compression. A nonlinear finite element model was developed and verified against the ball- and bolted-end conditions. The specimens are modelled precisely for the numerical investigation using finite element analysis as done in the column tests carefully undercontrolled. Both geometric and material nonlinearities are included in the finite element model. The predicted column strengths by the numerical analysis are compared with the design column strengths calculated using the North American Standards for cold-formed steel structures. It is shown that the design column strengths calculated from the specification are generally conservative for cold-formed steel angle sections. Results from the FEA correlate well with experimental data, NAS-2007 and BS: 5950 (Part 5) predictions. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
43. JUMPIN' JACK FLASH.
- Author
-
SMITH, JACK
- Subjects
- *
FLASH fiction , *COMPRESSION (Audiology) , *STANDARD language , *EXPERIMENTS , *PERIODICALS ,WRITING - Abstract
The article offers suggestions for writing flash fiction along with places to be submitted and sold. Topics discussed include several challenges faced by flash fictions which includes compression and experimentation, existence of compelling language and lazy sentence structure in flash stories, and need for creating a collection of stories for submission to magazines and presses.
- Published
- 2017
44. JBL Marks 70th Anniversary.
- Subjects
- *
ANNIVERSARIES , *JBL audio equipment , *GUITAR amplifiers , *COMPRESSION (Audiology) - Abstract
The article profiles audio electronics company JBL as it celebrates its 70th anniversary. It traces the lineage of JBL to the late 1920s during the development of woofers and compression drivers used in the Shearer Horn System for the early cinema, as well as the creation of the Cabaret series guitar components. It highlights JBL's venture with the launch of EON products, and the success of its VerTec line arrays and M2 15" floor-standing audio monitor.
- Published
- 2017
45. Honeycomb phononic crystals with self-similar hierarchy.
- Author
-
Mousanezhad, Davood, Ghosh, Ranajay, Vaziri, Ashkan, Babaee, Sahab, Bertoldi, Katia, and Mahdi, Elsadig
- Subjects
- *
HONEYCOMB structures , *PHONONIC crystals , *HIERARCHY of effects model (Communication) , *BAND gaps , *COMPRESSION (Audiology) , *TWO-dimensional models - Abstract
We highlight the effect of structural hierarchy and deformation on band structure and wave-propagation behavior of two-dimensional phononic crystals. Our results show that the topological hierarchical architecture and instability-induced pattern transformations of the structure under compression can be effectively used to tune the band gaps and directionality of phononic crystals. The work provides insights into the role of structural organization and hierarchy in regulating the dynamic behavior of phononic crystals, and opportunities for developing tunable phononic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
46. Performance Comparison of HEVC and H.264/AVC Standards in Broadcasting Environments.
- Author
-
Dissanayake, Maheshi B. and Abeyrathna, Dilanga L. B.
- Subjects
VIDEO coding ,COMPRESSION (Audiology) ,BANDWIDTHS ,NUMERICAL analysis ,SCALABILITY - Abstract
High Efficiency Video Coding (HEVC) is the most recent video codec standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. The main goal of this newly introduced standard is for catering to high-resolution video in low bandwidth environments with a higher compression ratio. This paper provides a performance comparison between HEVC and H.264/AVC video compression standards in terms of objective quality, delay, and complexity in the broadcasting environment. The experimental investigation was carried out using six test sequences in the random access configuration of the HEVC test model (HM), the HEVC reference software. This was also carried out in similar configuration settings of the Joint Scalable Video Module (JSVM), the official scalable H.264/AVC reference implementation, running on a single layer mode. According to the results obtained, the HM achieves more than double the compression ratio compared to that of JSVM and delivers the same video quality at half the bitrate. Yet, the HM encodes two times slower (at most) than JSVM. Hence, it can be concluded that the application scenarios of HM and JSVM should be judiciously selected considering the availability of system resources. For instance, HM is not suitable for low delay applications, but it can be used effectively in low bandwidth environments. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
47. Effect of Human Auditory Efferent Feedback on Cochlear Gain and Compression.
- Author
-
Yasin, Ifat, Drga, Vit, and Plack, Christopher J.
- Subjects
- *
OLIVARY nucleus , *ACOUSTIC nerve , *PSYCHOACOUSTICS , *BRAIN stem , *AUDITORY pathways , *COMPRESSION (Audiology) - Abstract
The mammalian auditory system includes abrainstem-mediated efferent pathway from the superior olivary complex byway of the medial olivocochlear system, which reduces the cochlear response to sound (Warr and Guinan, 1979; Liberman et al., 1996). The human medial olivocochlear response has an onset delay of between 25 and 40 ms and rise and decay constants in the region of280 and 160 ms, respectively (Backus and Guinan, 2006). Physiological studies with nonhuman mammals indicate that onset and decay characteristics of efferent activation are dependent on the temporal and level characteristics of the auditory stimulus (Bacon and Smith, 1991; Guinan and Stankovic, 1996). This study uses a novel psychoacoustical masking technique using aprecursor sound to obtain a measure of the efferent effect in humans. This technique avoids confounds currently associated with other psychoacoustical measures. Both temporal and level dependency of the efferent effect was measured, providing a comprehensive measure of the effect of human auditory efferents on cochlear gain and compression. Results indicate that aprecursor (>20 dB SPL) induced efferent activation, resulting in a decrease in both maximum gain and maximum compression, with linearization of the compressive function for input sound levels between 50 and 70 dB SPL. Estimated gain decreased as precursor level increased, and increased as the silent interval between the precursor and combined masker-signal stimulus increased, consistent with a decay of the efferent effect. Human auditory efferent activation linearizes the cochlear response for mid-level sounds while reducing maximum gain. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
48. The Hearing-Aid Speech Perception Index (HASPI).
- Author
-
Kates, James M. and Arehart, Kathryn H.
- Subjects
- *
HEARING aids , *SPEECH perception , *INTELLIGIBILITY of speech , *DEAFNESS , *NONLINEAR theories , *COMPRESSION (Audiology) - Abstract
This paper presents a new index for predicting speech intelligibility for normal-hearing and hearing-impaired listeners. The Hearing-Aid Speech Perception Index (HASPI) is based on a model of the auditory periphery that incorporates changes due to hearing loss. The index compares the envelope and temporal fine structure outputs of the auditory model for a reference signal to the outputs of the model for the signal under test. The auditory model for the reference signal is set for normal hearing, while the model for the test signal incorporates the peripheral hearing loss. The new index is compared to indices based on measuring the coherence between the reference and test signals and based on measuring the envelope correlation between the two signals. HASPI is found to give accurate intelligibility predictions for a wide range of signal degradations including speech degraded by noise and nonlinear distortion, speech processed using frequency compression, noisy speech processed through a noise-suppression algorithm, and speech where the high frequencies are replaced by the output of a noise vocoder. The coherence and envelope metrics used for comparison give poor performance for at least one of these test conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
49. Lossless Compression Method for Acoustic Waveform Data Based on Linear Prediction and Bit-recombination Mark Coding.
- Author
-
Ming Cai, Wenxiao Qiao, Xiaodong Ju, and Xiaohua Che
- Subjects
ACOUSTIC arrays ,LINEAR acceleration ,LOGGING ,COMPRESSION (Audiology) ,WAVE analysis ,DATA compression - Abstract
In acoustic logging, large amounts of data put forward severe challenges for data transmission, storage and processing. Data compression techniques, to some extent, may relieve this problem. In this paper, we first review the basic principle of the linear prediction, and appropriately improve common optimal linear prediction method to get a new optimal linear prediction method that maps integers to integers. Then, we explore an appropriate bit-recombination mark coding approach according to the characteristics of prediction errors sequence. Finally, we propose a new lossless compression method for acoustic waveform data based on linear prediction and bit-recombination mark coding. The compression and decompression programs are developed according to the proposed method. Field acoustic logging waveform data are then applied to compression and decompression tests and the compression performances of our method and several other lossless compression methods are compared and analyzed. Test results validate the correctness of our method and demonstrate its advantages. The new method is potentially applicable to acoustic waveform data compression. [ABSTRACT FROM AUTHOR]
- Published
- 2013
50. Compression: From Cochlea to Cochlear Implants
- Author
-
Sid Bacon, Richard R. Fay, Sid Bacon, and Richard R. Fay
- Subjects
- Cochlea, Compression (Audiology), Auditory perception, Cochlear implants
- Abstract
The Springer Handbook of Auditory Research presents a series of comp- hensive and synthetic reviews of the fundamental topics in modern au- tory research.The volumes are aimed at all individuals with interests in hearing research including advanced graduate students, post-doctoral researchers, and clinical investigators.The volumes are intended to int- duce new investigators to important aspects of hearing science and to help established investigators to better understand the fundamental theories and data in?elds of hearing that they may not normally follow closely. Each volume is intended to present a particular topic comprehensively, and each chapter will serve as a synthetic overview and guide to the lit- ature.As such the chapters present neither exhaustive data reviews nor original research that has not yet appeared in peer-reviewed journals.The volumes focus on topics that have developed a solid data and conceptual foundation rather than on those for which a literature is only beginning to develop. New research areas will be covered on a timely basis in the series as they begin to mature.
- Published
- 2004
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