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Acoustic perception of the automotive environment has the potential to advance driving potentials with enhanced safety. The challenge arises when these acoustic perception systems need to perform under resource and power constraints on edge devices. Neuromorphic computing has introduced spiking neural networks in the context of ultra-low power sensory edge devices. Spiking architectures leverage biological plausibility to achieve computational capabilities, accurate performance, and great compatibility with neuromorphic hardware. In this work, we explore the depths of spiking neurons and feature components with the acoustic scene analysis task for siren sounds. This research work aims to address the qualitative analysis of sliding windows' variation on the feature extraction front of the preprocessing pipeline. Optimization of the parameters to exploit the feature extraction stage facilitates the advancement of the performance of the acoustics anomaly detection task. We exploit the parameters for mel spectrogram features and FFT calculations, prone to be suitable for computations in hardware. We conduct experiments with different window sizes and the overlapping ratio within the windows. We present our results for performance measures like accuracy and onset latency to provide an insight on the choice of optimal window. The non-trivial motivation of this research is to understand the effect of encoding behavior of spiking neurons with different windows. We further investigate the heterogeneous nature of membrane and synaptic time constants and their impact on the accuracy of anomaly detection. On a large scale audio dataset comprising of siren sounds and road traffic noises, we obtain accurate predictions of siren sounds using a recurrent spiking neural network. The baseline dataset comprising siren and noise sequences is enriched with a bird dataset to evaluate the model with unseen samples. [ABSTRACT FROM AUTHOR]

Highly performance flexible strain sensor is a crucial component for wearable devices, human‐machine interfaces, and e‐skins. However, the sensitivity of the strain sensor is highly limited by the strain range for large destruction of the conductive network. Here the quasi‐1D conductive network (QCN) is proposed for the design of an ultra‐sensitive strain sensor. The orientation of the conductive particles can effectively reduce the number of redundant percolative pathways in the conductive composites. The maximum sensitivity will reach the upper limit when the whole composite remains only "one" percolation pathway. Besides, the QCN structure can also confine the tunnel electron spread through the rigid inclusions which significantly enlarges the strain‐resistance effect along the tensile direction. The strain sensor exhibits state‐of‐art performance including large gauge factor (862227), fast response time (24 ms), good durability (cycled 1000 times), and multi‐mechanical sensing ability (compression, bending, shearing, air flow vibration, etc.). Finally, the QCN sensor can be exploited to realize the human‐machine interface (HMI) application of acoustic signal recognition (instrument calibration) and spectrum restoration (voice parsing). [ABSTRACT FROM AUTHOR]

The evaluation of a soundscape is a challenging task as the object of study is not a stationary event of sensation but rather a dynamic and complex scene stretching over a specific period. To do justice to the time dimension in such acoustic scenes, we utilized the Continuous Evaluation Procedure (CEP). Extending common standard instruments asking participants for a singular integral at the end of the sound experience (e.g., on a rating scale), the participants in this study were enabled to continuously evaluate the evolving acoustic scene of accelerating electrified vehicles (EVs) using CEP. With the increasing electrification of powertrains in the automotive industry, acoustic engineers face the challenge of defining innovative sounds using the availabilities of now low-noise emission platforms of EVs that deviate in their noise profiles from familiar but technologically outdated internal combustion engine vehicles (ICEVs), which have defined the general sound schemes for more than a century. To capture dynamic aspects in the quality perception of powertrain noise in EVs, we asked 37 participants to evaluate acoustic recordings of different vehicles in varying acceleration modes in a high-quality three-dimensional (3D) acoustic simulator. Thereby, we revealed much more detailed and timedependent quality aspects, which do not come forth in an integral singular measure (ISM) where all impressions experienced during the ongoing acoustic scene are blended together. We, therefore, propagate the systematic application of the CEP method when it comes to the qualitative evaluation of transient acoustic scenes. CEP opens the great opportunity to unfold, detect, and analyze dynamic effects in soundscapes and noise profiles, but of any kind of acoustic signal. [ABSTRACT FROM AUTHOR]

Abstract Highly performance flexible strain sensor is a crucial component for wearable devices, human‐machine interfaces, and e‐skins. However, the sensitivity of the strain sensor is highly limited by the strain range for large destruction of the conductive network. Here the quasi‐1D conductive network (QCN) is proposed for the design of an ultra‐sensitive strain sensor. The orientation of the conductive particles can effectively reduce the number of redundant percolative pathways in the conductive composites. The maximum sensitivity will reach the upper limit when the whole composite remains only “one” percolation pathway. Besides, the QCN structure can also confine the tunnel electron spread through the rigid inclusions which significantly enlarges the strain‐resistance effect along the tensile direction. The strain sensor exhibits state‐of‐art performance including large gauge factor (862227), fast response time (24 ms), good durability (cycled 1000 times), and multi‐mechanical sensing ability (compression, bending, shearing, air flow vibration, etc.). Finally, the QCN sensor can be exploited to realize the human‐machine interface (HMI) application of acoustic signal recognition (instrument calibration) and spectrum restoration (voice parsing).

Acoustic perception of the automotive environment has the potential to advance driving potentials with enhanced safety. The challenge arises when these acoustic perception systems need to perform under resource and power constraints on edge devices. Neuromorphic computing has introduced spiking neural networks in the context of ultra-low power sensory edge devices. Spiking architectures leverage biological plausibility to achieve computational capabilities, accurate performance, and great compatibility with neuromorphic hardware. In this work, we explore the depths of spiking neurons and feature components with the acoustic scene analysis task for siren sounds. This research work aims to address the qualitative analysis of sliding windows’ variation on the feature extraction front of the preprocessing pipeline. Optimization of the parameters to exploit the feature extraction stage facilitates the advancement of the performance of the acoustics anomaly detection task. We exploit the parameters for mel spectrogram features and FFT calculations, prone to be suitable for computations in hardware. We conduct experiments with different window sizes and the overlapping ratio within the windows. We present our results for performance measures like accuracy and onset latency to provide an insight on the choice of optimal window. The non-trivial motivation of this research is to understand the effect of encoding behavior of spiking neurons with different windows. We further investigate the heterogeneous nature of membrane and synaptic time constants and their impact on the accuracy of anomaly detection. On a large scale audio dataset comprising of siren sounds and road traffic noises, we obtain accurate predictions of siren sounds using a recurrent spiking neural network. The baseline dataset comprising siren and noise sequences is enriched with a bird dataset to evaluate the model with unseen samples.

The major goal of psychoarchaeoacoustics is to understand the psychology behind motivations and emotions of past communities when selecting certain acoustic environments to set activities involving the production of paintings and carvings. Within this framework, the present study seeks to explore whether a group of archaeological rock art sites in Altai (Siberia, Russia) are distinguished by particular acoustic imprints that elicit distinct reactions on listeners, in perceptual and emotional terms. Sixty participants were presented with a series of natural sounds convolved with six impulse responses from Altai, three of them recorded in locations in front of rock art panels and three of them in front of similar locations but without any trace of rock art. Participants were interrogated about their subjective perception of the sounds presented, using 10 psychoacoustic and emotional scales. The mixed ANOVA analyses carried out revealed that feelings of "presence," "closeness," and "tension" evoked by all sounds were significantly influenced by the location. These effects were attributed to the differences in reverberation between the locations with and without rock art. Despite results are not consistent across all the studied rock art sites, and acknowledging the presence of several limitations, this study highlights the significance of its methodology. It stresses the crucial aspect of incorporating the limitations encountered in shaping future research endeavors. [ABSTRACT FROM AUTHOR]

The major goal of psychoarchaeoacoustics is to understand the psychology behind motivations and emotions of past communities when selecting certain acoustic environments to set activities involving the production of paintings and carvings. Within this framework, the present study seeks to explore whether a group of archaeological rock art sites in Altai (Siberia, Russia) are distinguished by particular acoustic imprints that elicit distinct reactions on listeners, in perceptual and emotional terms. Sixty participants were presented with a series of natural sounds convolved with six impulse responses from Altai, three of them recorded in locations in front of rock art panels and three of them in front of similar locations but without any trace of rock art. Participants were interrogated about their subjective perception of the sounds presented, using 10 psychoacoustic and emotional scales. The mixed ANOVA analyses carried out revealed that feelings of “presence,” “closeness,” and “tension” evoked by all sounds were significantly influenced by the location. These effects were attributed to the differences in reverberation between the locations with and without rock art. Despite results are not consistent across all the studied rock art sites, and acknowledging the presence of several limitations, this study highlights the significance of its methodology. It stresses the crucial aspect of incorporating the limitations encountered in shaping future research endeavors.

The yellow-line quaker Agrochola macilenta Hbn. and the herald moth Scoliopteryx libatrix L., which are noctuid moths, were tested with sequences of pulses resembling bat echolocation signals in conditions of fixed flight. Changes in the directional aerodynamic force were studied in flying moths in relation to the amplitude and filling frequency of acoustic stimuli in the frequency range 10–140 kHz. Averaged frequency-threshold plots for exemplars of both species were similar in shape to audiograms from moth tympanic organ auditory receptors, though the thresholds recorded in behavioral tests were an average of 35 dB lower than the thresholds of tympanic organ auditory receptors. The possible mechanisms regulating acoustic sensitivity in intact moths and influences on the results obtained by recording motor activity in the experimental moths are discussed. [ABSTRACT FROM AUTHOR]

The current research aimed to identify the nature of the psychometric properties of the phonological perception scale for hearing impaired children, and the scale consists of ten dimensions, namely: (dividing the sentence into words - dividing the word into syllables - dividing syllables into sounds - dividing the word into sounds - merging sounds to produce sound syllables - Determining the beginning sound in each word - Determining the ending sound in each word - Training to delete the first sound in the word - Recognizing the initial rhyme - Determining the ending sounds). The psychometric research sample consisted of (50) hearing-impaired children, ranging in age from The time between (9-12) years, with a mean of (11.14) and a standard deviation of (0.16), was done by using appropriate statistical treatments. It makes it a usable tool to achieve the goals for which it was set, and then the researcher recommends conducting more studies aimed at improving the vocal perception of this group using the current scale. [ABSTRACT FROM AUTHOR]

To explore the effects of acoustic perception on outdoor thermal comfort, acoustic perception in five typical open spaces in a campus in China's cold region with common soundscapes was evaluated by using meteorological measures, sound level devices, and a questionnaire survey. Eight adjectives were used to evaluate an individual's acoustic perception, and the physiological equivalent temperature (PET) was selected as a thermal index. The correlations between acoustic perception and thermal comfort in these typical open spaces were further analyzed. We demonstrated that: (1) Acoustic sensation and comfort varied significantly among sound types (STPs). Respondents reported pleasant perceptions of broadcasting music, running water and birdsong, and wind (a gentle breeze) and insects. (2) Although there was no significant difference in the thermal sensation vote (TSV), we found large differences in the thermal comfort vote (TCV) among STPs. (3) The respondents' neutral PET (NPET) varied among STPs. In autumn, the ranked order of NPET was machines > running water and birdsong > crowds > broadcasting music > wind (a gentle breeze) and insects. In winter, the order of the NPET was machines > wind (a gentle breeze) and insects > crowds > broadcasting music > running water and birdsong. (4) When people perceived "acoustic comfort", their TSV improved, and vice versa. [ABSTRACT FROM AUTHOR]

In ordinary public rooms absorbent ceilings are normally used. However, reflective material such as diffusers can also be useful to improve the acoustic performance for this type of environment. In this study, different combinations of absorbers and diffusers have been used. The study investigates whether a test group of 29 people perceived sound in an ordinary room differently depending on the type of treatment. Comparisons of the same position in a room for different configurations as well as different positions within one configuration were made. The subjective judgements were compared to the room acoustic measures T20, C50 and G and the difference in the values of these parameters. It was found that when evaluating the different positions in a room, the configuration including diffusers was perceived to a greater extent as being similar in the different positions in the room when compared to the configuration with absorbers on the walls. It was also seen that C50 was the parameter that mainly affected the perception, with the difference needing to be 2 dB to recognize a difference. However, the room acoustic measurements could not fully explain the differences obtained in perception. In addition, the subjective sound image created by different types of treatments was also shown to have an important impact on the perception.

Spatial memory relies on encoding, storing, and retrieval of knowledge about objects' positions in their surrounding environment. Blind people have to rely on sensory modalities other than vision to memorize items that are spatially displaced, however, to date, very little is known about the influence of early visual deprivation on a person's ability to remember and process sound locations. To fill this gap, we tested sighted and congenitally blind adults and adolescents in an audio-spatial memory task inspired by the classical card game "Memory." In this research, subjects (blind, n = 12; sighted, n = 12) had to find pairs among sounds (i.e., animal calls) displaced on an audio-tactile device composed of loudspeakers covered by tactile sensors. To accomplish this task, participants had to remember the spatialized sounds' position and develop a proper mental spatial representation of their locations. The test was divided into two experimental conditions of increasing difficulty dependent on the number of sounds to be remembered (8 vs. 24). Results showed that sighted participants outperformed blind participants in both conditions. Findings were discussed considering the crucial role of visual experience in properly manipulating auditory spatial representations, particularly in relation to the ability to explore complex acoustic configurations. [ABSTRACT FROM AUTHOR]

Spatial memory relies on encoding, storing, and retrieval of knowledge about objects’ positions in their surrounding environment. Blind people have to rely on sensory modalities other than vision to memorize items that are spatially displaced, however, to date, very little is known about the influence of early visual deprivation on a person’s ability to remember and process sound locations. To fill this gap, we tested sighted and congenitally blind adults and adolescents in an audio-spatial memory task inspired by the classical card game “Memory.” In this research, subjects (blind, n = 12; sighted, n = 12) had to find pairs among sounds (i.e., animal calls) displaced on an audio-tactile device composed of loudspeakers covered by tactile sensors. To accomplish this task, participants had to remember the spatialized sounds’ position and develop a proper mental spatial representation of their locations. The test was divided into two experimental conditions of increasing difficulty dependent on the number of sounds to be remembered (8 vs. 24). Results showed that sighted participants outperformed blind participants in both conditions. Findings were discussed considering the crucial role of visual experience in properly manipulating auditory spatial representations, particularly in relation to the ability to explore complex acoustic configurations.

Black-capped chickadee (Poecile atricapillus) chick-a-dee calls differ acoustically depending on flock membership, individual identity, and species identity. Other chickadee vocalizations, including their tseet call and fee-bee song, differ depending on the sex of the signaler. In Experiment 1, we used an operant go/no-go discrimination task to investigate if black-capped chickadees perceive any acoustic differences between male- and female-produced chick-a-dee calls. Manufactured calls that included both male- and female-produced portions were also tested. We conducted a second experiment in which the terminal “-dee” portions of the same chick-a-dee stimuli as used in Experiment 1 were removed. In both experiments, there was no evidence for category learning. Birds did not transfer responding from learned contingencies to untrained stimuli. These results indicate that, while it may be biologically relevant to attend to sex of a signaler in reproductive-critical vocalizations such as the fee-bee song, there may be no benefit for this information to be transmitted in chick-a-dee calls, which are mainly used in situations unrelated to reproduction.

To explore the effects of acoustic perception on outdoor thermal comfort, acoustic perception in five typical open spaces in a campus in China’s cold region with common soundscapes was evaluated by using meteorological measures, sound level devices, and a questionnaire survey. Eight adjectives were used to evaluate an individual’s acoustic perception, and the physiological equivalent temperature (PET) was selected as a thermal index. The correlations between acoustic perception and thermal comfort in these typical open spaces were further analyzed. We demonstrated that: (1) Acoustic sensation and comfort varied significantly among sound types (STPs). Respondents reported pleasant perceptions of broadcasting music, running water and birdsong, and wind (a gentle breeze) and insects. (2) Although there was no significant difference in the thermal sensation vote (TSV), we found large differences in the thermal comfort vote (TCV) among STPs. (3) The respondents’ neutral PET (NPET) varied among STPs. In autumn, the ranked order of NPET was machines > running water and birdsong > crowds > broadcasting music > wind (a gentle breeze) and insects. In winter, the order of the NPET was machines > wind (a gentle breeze) and insects > crowds > broadcasting music > running water and birdsong. (4) When people perceived “acoustic comfort”, their TSV improved, and vice versa.

The multifaceted ability to produce, transmit, receive, and respond to acoustic signals is widespread in animals and forms the basis of the interdisciplinary science of bioacoustics. Bioacoustics research methods, including sound recording and playback experiments, are applicable in cognitive research that centers around the processing of information from the acoustic environment. We provide an overview of bioacoustics techniques in the context of cognitive studies and make the case for the importance of bioacoustics in the study of cognition by outlining some of the major cognitive processes in which acoustic signals are involved. We also describe key considerations associated with the recording of sound and its use in cognitive applications. Based on these considerations, we provide a set of recommendations for best practices in the recording and use of acoustic signals in cognitive studies. Our aim is to demonstrate that acoustic recordings and stimuli are valuable tools for cognitive researchers when used appropriately. In doing so, we hope to stimulate opportunities for innovative cognitive research that incorporates robust recording protocols. This article is categorized under:Neuroscience > CognitionPsychology > Theory and MethodsNeuroscience > BehaviorNeuroscience > Cognition [ABSTRACT FROM AUTHOR]

Both language and music are universal and characteristic for humans. The evolution of the cognitive abilities underlying language and music are widely debated. A core question is whether these abilities find their origins in a modification or extension of general cognitive abilities for processing auditory input also present in other species. If so, comparative studies of nonhuman animals should reveal similarities in processing abilities. In this paper, we review some examples of such studies. We focus on whether birds (in particular zebra finches, Taeniopygia guttata , and budgerigars, Melopsittacus undulates) can detect structural patterns based on relational rather than on physical similarities among auditory stimuli – an essential ability for processing and producing language and music. We briefly discuss why birds are suitable model species. Next, we discuss three domains of pattern detection: the ability to (1) detect 'grammatical rules' underlying sound strings; (2) perceive regular rhythms and (3) spontaneously group separate sounds into a larger pattern. In all of these there is evidence that birds show some ability to detect relational patterns. However, there is also variation between species: while budgerigars show relational rule learning, zebra finches attend to local physical similarities between sound strings used for training and testing. For rhythm detection, zebra finches and budgerigars show no clear differences. However, a broader comparison indicates that here too differences are present in the extent to which different bird species attend to relational patterns or to local features. Finally, spontaneous grouping of sounds was shown in zebra finches. The clear variation among bird species in their perceptual and cognitive abilities, in combination with their accessibility for experimental studies, provides opportunities to study the variation in auditory processing mechanisms and how these evolved. This may also provide hypotheses for the evolution of these abilities in humans. • The evolution of the cognitive mechanisms underlying music and language is debated. • Comparative studies in birds provide insights in the evolution of these mechanisms. • Some species can learn grammatic rules, perceive rhythm and show perceptual grouping. • Interspecific variation provides a tool to study how mechanisms and variation evolve. [ABSTRACT FROM AUTHOR]

Abstract The effects of indoor water sounds on traffic noise perception were investigated under three room temperatures of 18 °C, 24 °C, and 30 °C through listening experiments with 54 participants. Two types and four levels of water sounds (35, 40, 45, and 50 dBA) were presented with four levels of traffic noise (45, 50, 55, and 60 dBA) in an indoor environmental test laboratory. Water sounds were recorded using a simple indoor fountain comprising a submersible pump and two types of nozzles (foam-jet and mushroom), which generated different water sound spectra. The listeners assessed the thermal and acoustic environments on eleven adjective attributes, representing negative acoustic attributes, positive acoustic attributes, acoustic comfort, thermal comfort, and overall comfort. The results showed that indoor water sounds enhanced pleasantness, calmness, and naturalness without increment of noisiness, loudness, or annoyance in the 30 °C condition, while no perceptual improvement of traffic noise was found in the 18 °C and 24 °C conditions. Room temperature affected both thermal perception and acoustic perception. Water sounds affected not only acoustic perception, but also thermal and overall indoor environmental comfort. A just noticeable water sound level was preferred to mitigate intrusive traffic noise perceptually in a room. The noise perceived in a room should be described by both negative and positive adjectives together, in order to evaluate the effects of indoor environment, such as water sounds and temperature, on noise perception. [ABSTRACT FROM AUTHOR]

In birds and higher mammals, auditory experience during development is critical to discriminate sound patterns in adulthood. However, the neural and molecular nature of this acquired ability remains elusive. In fruit flies, acoustic perception has been thought to be innate. Here we report, surprisingly, that auditory experience of a species-specific courtship song in developing Drosophila shapes adult song perception and resultant sexual behavior. Preferences in the song-response behaviors of both males and females were tuned by social acoustic exposure during development. We examined the molecular and cellular determinants of this social acoustic learning and found that GABA signaling acting on the GABAA receptor Rdl in the pC1 neurons, the integration node for courtship stimuli, regulated auditory tuning and sexual behavior. These findings demonstrate that maturation of auditory perception in flies is unexpectedly plastic and is acquired socially, providing a model to investigate how song learning regulates mating preference in insects.

Abstract Cross-modal effects of sound and illuminance were investigated in an indoor environmental chamber with 60 university students (30 men and 30 women) aged 18–26 years. A within-subject factorial design was employed with four independent variables: noise level (45, 55, 65, and 75 dBA), noise type (Music, Water, Babble, and Fan), illuminance level (150, 500, and 1000 lx), and sex (female or male). The test conditions represented daily indoor environments, which was moderately noisy and did not present severe lighting conditions. Acoustic (loudness, annoyance, pleasantness, and naturalness) and visual (brightness and relaxation) semantic attributes were assessed using an 11-point numeric scale. The illuminance level of the ambient lighting system did not affect acoustic perception. Brightness was not altered by sound, but relaxation was affected by sound. Cross-modal interactions were asymmetric between sound and illuminance in indoor environmental settings. Women were more sensitive to the perception of both acoustic and illuminance stimuli than men, at high level of stimulation. [ABSTRACT FROM AUTHOR]

This article examines the essential role of reverberation in everyday spatial experience and argues that the perception and production of reverberation - along with the related concept of resonance - is an example of an innate mimetic capacity residing in both living beings and seemingly inert matter. Reverberation, and acoustic experience more generally, are explored in relation to urban space, with attention paid to the transformation of sense experience in modernity. Drawing on a range of authors, with reference to the work of Walter Benjamin in particular, this article proceeds from a primarily theoretical level to that of concrete human experience, with the example of buskers (street musicians) who perform in the highly reverberant spaces of Montreal's underground metro system. Drawing on the author's ethnographic research among metro musicians, this article demonstrates that reverberation is a vital element in busker practices and experience, and argues that, in their practices and in their effects on space and passersby, metro buskers make evident - make perceptible - the mimetically reverberant relations between body and space, and between self and other. [ABSTRACT FROM AUTHOR]

The sound environment and acoustic perception of open-air markets, which are very common in high-density urban open spaces, play important roles in terms of the urban soundscape. Based on objective and subjective measurements of a typical temporary open-air market in Harbin city, China, the effects of the temporary open-air market on the sound environment and acoustic perception were studied, considering different crowd densities. It was observed that a temporary open-air market without zoning increases the sound pressure level and subjective loudness by 2.4 dBA and 0.21 dBA, respectively, compared to the absence of a temporary market. Different from the sound pressure level and subjective loudness, the relationship between crowd density and the perceived acoustic comfort is parabolic. Regarding the effect of a temporary open-air market with different zones on the sound environment and acoustic perception, when the crowd densities were the same, subjective loudness in the fruit and vegetable sales area was always higher than in the food sales area and the clothing sales area. In terms of acoustic comfort, with an increase in crowd density, acoustic comfort in the fruit and vegetable sales area decreased, and acoustic comfort in the food sales area and the clothing sales area exhibited a parabolic change trend of increase followed by decrease. Overall, acoustic comfort can be effectively improved by better planning temporary open-air markets in high-density urban open spaces. [ABSTRACT FROM AUTHOR]

The acoustic environment of restaurants is important for diners. Based on acoustic measurements and a questionnaire survey of typical restaurants, differences in diners' conversation behaviour and acoustic perception were analysed. Three dining styles were compared (centralized, separate, and dispersed), and crowd density and background music were considered. Several interesting findings were gained. First, dining styles affected conversation behaviour. When there were four or more diners per table, conversation increased compared to when there were three or fewer; and background music did not reduce conversation. With the centralized style, the proportion of speech diners heard was greater than for the other two dining styles, even as crowd density increased. Second, dining styles affected sound pressure level. With background music, the separate style decreased sound pressure level more effectively than the other two styles when crowd density was low, and without background music, the separate style decreased sound pressure level more effectively than the other two dining styles irrespective of crowd density. Dining styles also affected acoustic comfort: with the centralized and separate styles, acoustic comfort took on a parabolic shape, first increasing and then decreasing as crowd density increased, while with the dispersed style, as crowd density increased, the acoustic comfort of diners decreased. [ABSTRACT FROM AUTHOR]

Humans have a strong tendency to spontaneously group visual or auditory stimuli together in larger patterns. One of these perceptual grouping biases is formulated as the iambic/trochaic law, where humans group successive tones alternating in pitch and intensity as trochees (high-low and loud-soft) and alternating in duration as iambs (short-long). The grouping of alternations in pitch and intensity into trochees is a human universal and is also present in one non-human animal species, rats. The perceptual grouping of sounds alternating in duration seems to be affected by native language in humans and has so far not been found among animals. In the current study, we explore to which extent these perceptual biases are present in a songbird, the zebra finch. Zebra finches were trained to discriminate between short strings of pure tones organized as iambs and as trochees. One group received tones that alternated in pitch, a second group heard tones alternating in duration, and for a third group, tones alternated in intensity. Those zebra finches that showed sustained correct discrimination were next tested with longer, ambiguous strings of alternating sounds. The zebra finches in the pitch condition categorized ambiguous strings of alternating tones as trochees, similar to humans. However, most of the zebra finches in the duration and intensity condition did not learn to discriminate between training stimuli organized as iambs and trochees. This study shows that the perceptual bias to group tones alternating in pitch as trochees is not specific to humans and rats, but may be more widespread among animals. [ABSTRACT FROM AUTHOR]

Acoustic perception in concert halls has been a topic of research of great interest over the last century. It has been studied through physical and subjective parameters. Nevertheless, a concert in an auditorium is a multi-sensorial experience; so that the acoustic perception may be influenced by other non-acoustical attributes. Therefore, the aim of the present study was to analyze whether architectural variables (visual component) affect acoustic perception in concert halls and quantify this influence. This analysis was carried out implementing the Semantic Differential method and differentiating among experts and non-experts users. A total of 310 subjects assessed in situ 17 concert halls. Results showed that acoustic perception was influenced by the visual component, and acoustic parameters had an influence on architecture as well. However, when separating both groups, it was found that experts were able to isolate acoustic variables from architecture when evaluating the sound quality of a venue. [ABSTRACT FROM AUTHOR]

Metrical phonology is the perceptual 'strength' in language of some syllables relative to others. The ability to perceive lexical stress is important, as it can help a listener segment speech and distinguish the meaning of words and sentences. Despite this importance, there has been little comparative work on the perception of lexical stress across species. We used a go/no-go operant paradigm to train human participants and budgerigars ( Melopsittacus undulatus) to distinguish trochaic (stress-initial) from iambic (stress-final) two-syllable nonsense words. Once participants learned the task, we presented both novel nonsense words, and familiar nonsense words that had certain cues removed (e.g., pitch, duration, loudness, or vowel quality) to determine which cues were most important in stress perception. Members of both species learned the task and were then able to generalize to novel exemplars, showing categorical learning rather than rote memorization. Tests using reduced stimuli showed that humans could identify stress patterns with amplitude and pitch alone, but not with only duration or vowel quality. Budgerigars required more than one cue to be present and had trouble if vowel quality or amplitude were missing as cues. The results suggest that stress patterns in human speech can be decoded by other species. Further comparative stress-perception research with more species could help to determine what species characteristics predict this ability. In addition, tests with a variety of stimuli could help to determine how much this ability depends on general pattern learning processes versus vocalization-specific cues. [ABSTRACT FROM AUTHOR]

Stress is known to elicit various adaptive or maladaptive responses in the nervous system function. Psychophysical studies have revealed that stress exposure induced the changes in auditory response that can be interpreted as a transient, stress-induced hypersensitivity to sounds. However, the underlying neural mechanism remains unresolved. Thus, in this study, we explored the neural activities of the auditory cortex (AC) in response to stress. We elicited stress by physically immobilizing rats and recorded the extracellular single-unit activities through the electrodes chronically implanted in the AC of rats. By comparing the spike activities of the same rat before, during and after immobilization, we found temporal and significant changes in the sound-evoked neural activities. In most cases, acute restraint stress enhanced neural responses evoked by pure-tones and click-trains, but in a minority of neurons, stress suppressed responses. The immobilization-induced enhancement was more frequently found in the neurons that originally had a low responsibility for sound stimuli. The enhancement effects on pure-tone response were reflected by an increase of response magnitude, decrease of response latency, and extension of bandwidth of tuning curve (BW). But the spontaneous firing rate and best frequency (BF) remained unchanged. Stress also increased the ability of neural response to synchronize to click-trains, even in the neurons whose response magnitude was not significantly increased. Taken together, these results provide direct evidence that stress alters the function of auditory system at the level of AC. [ABSTRACT FROM AUTHOR]

It has been proposed that leks arise because of increased mating benefits in aggregations of displaying males, and some evidence supports this hypothesis. But observations also indicate that lekking aggregations include only a small percentage of the males in a population, implying that certain factors limit lek size. Potential factors include increasing travel costs to find and form large but distant aggregations, greater attraction of predators and higher levels of aggression. Any one of these constraints may cause the number of females arriving at larger leks to decelerate such that per capita male attractiveness, and hence mating success, declines above an optimum lek size. None the less, relatively little empirical work has examined what determines lek size. In particular the possibility that cognitive aspects might constrain lek size has rarely been considered. We studied this question in Achroia grisella , an acoustic moth in which singing males form small aggregations that attract females. We created artificial leks in the laboratory and tested their relative attractiveness to females; we also tested male preferences to form and join such aggregations. Females preferred male aggregations over solitary singers, but the marginal per capita attractiveness of an aggregation of n + 2 males versus n males waned for n ≥ 5. Similarly we found that males were attracted to other males singing in the vicinity, but this effect disappeared for n ≥ 4. We infer that lek size is limited because the marginal per capita attractiveness of larger leks only occurs for small groups. This constraint probably arises because females distinguish leks by overall song rate but are neuroethologically incapable of discriminating rates above a threshold value corresponding to groups of four to six males. These findings emphasize the critical role that neural constraints may play in determining fundamental parameters of complex behaviours such as lekking. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the physiological role of the auditory cortex (AC) in acoustic perception is an essential issue in auditory neuroscience. By comparing sound discrimination behaviors in animals before and after AC lesion, many studies have demonstrated that AC is necessary for the perceptual process of human vowels and animal vocalizations, but is not necessary to discriminate simple acoustic parameters such as sound onset, intensity and duration. Because a lesion study cannot fully reveal the function of AC under normal conditions, in this study, we combined electrophysiological recording and psychophysical experiments on the same animal to investigate whether AC is involved in a simple auditory task. We recorded the neural activities of the primary auditory cortex (A1) using implanted electrodes, while freely-moving cats performed a tone-detection task in which they were required to lick a metal tube to obtain a food reward after hearing a tone pip. The performance of the cats’ behavioral response increased with the increase of tone intensity, and the neural activities of A1 covaried with the behavioral performance. Also, whether the tone-detection behavior was interfered by a wideband noise was dependent on whether the tone-evoked neural response was masked by the noise-evoked response. Our results did not support that A1 neurons directly associate with the cat''s behavioral decision; instead, they may mainly generate a neural representation of stimulus amplitude for further processing to determine whether a tone occurred or not. [Copyright &y& Elsevier]

To characterize their soundscape perception, preschool children were subjected to inclusive soundscape exposure conditions (both indoor and outdoor) and were asked to evaluate the soundscape in this study comprising two experiments. In Experiment 1, reliable soundscape perception dimensions for preschool children were formulated using semantic differential analysis. In Experiment 2, the relationship between the dimensions and the overall soundscape evaluation and acoustic characteristics was investigated. The principal component analysis resulted in three factors (eigenvalue> 1), namely pleasantness , peacefulness , and regularity , explaining 69.96% of the variance (48.70%, 13.13%, and 8.13%, respectively). Among them, pleasantness and peacefulness significantly contributed to the overall soundscape evaluation (preference), as the improvement attitude of these two factors led to a higher chance of a positive attitude towards the overall soundscape preference (i.e., "like"). L A50 and L A10 contributed significantly to the regression for pleasantness and peacefulness , accounting for 41.2% and 92.6% of the prediction variance, respectively. Regularity had no significant effect on the overall soundscape evaluation. In addition, no acoustic characteristics significantly predicted this factor. The outcome showed that preschool children are capable of multi-scale evaluation of diverse soundscapes, embodying their awareness of both the quality and influence of the acoustic environment. Their soundscape perception dimensions pertain to the features of the preschool period and are thus inconsistent with previous adults' soundscape dimensions. In addition, preschool children seem to desire mild and peaceful soundscapes under control. • Preschool children reported their perception of both indoor and outdoor soundscapes. • Preschoolers' soundscape perception dimensions: Pleasantness, Peacefulness, and Regularity. • Pleasantness and Peacefulness influenced the overall soundscape evaluation. • L A50 significantly contributed to the regression for Pleasantness. • L A10 significantly contributed to the regression for Peacefulness. [ABSTRACT FROM AUTHOR]

We report the results of an experiment designed to investigate whether captive cotton-top tamarins (Saguinus oedipus ) selectively call back to an absent cagemate. We removed 2 individuals living in separate cages (cycling through the colony so that each individual was removed 10 times) from the homeroom and played back calls produced by one of them. The caller's cagemate, residing in the homeroom, was more likely to be the first individual to call back antiphonally than any other individual in the colony was. In support of previous work using both habituation-discrimination and phonotaxic techniques, our results show that cotton-top tamarins can recognize cagemates and possibly individuals by voice alone, and that the antiphonal playback method provides yet another tool for investigating acoustic perception in nonhuman primates. [ABSTRACT FROM AUTHOR]

The trade-off between noise and temperature and their combined effects on discomfort were studied on 108 lightly clothed subjects (0.6 clo), individually exposed for 2 h in a climatic chamber. Every 10 min of the first hour, subjects could modify the experimental conditions by deciding a change in temperature or noise. However, any change in one parameter was experimentally associated with a fixed change in the other parameter according to eight predetermined designs and all trials for thermal improvement were detrimental to acoustic comfort and conversely. Four initial exposures started at thermoneutrality (24 °C) in a noisy environment (85 dBA, recorded fan noise), the reduction of noise being linked to a temperature change towards cool or warm climates. The other four conditions started at a low noise level (35 dBA) but in a cool (14 or 19 °C) or warm (29 or 34 °C) environment, the reduction of thermal discomfort towards 24 °C leading to a louder noise. After six possible voluntary changes, the environment was kept constant for 1 h. Ambient parameters, skin temperatures, and subjective estimates were recorded.Results showed that females accepted noisier environments than males, suggesting that thermal comfort is dominant for women. Noise was rated as the most unpleasant factor when initial conditions were noisy whereas temperature was the most disturbing factor when subjects began the experiment with thermal conditions far from thermoneutrality. Finally, although the combined effects of noise and temperature did not influence the physiological data, our results suggest that noise may alter thermal pleasantness in warm conditions. [Copyright &y& Elsevier]

Pair formation in the lesser wax moth, Achroia grisella (Lepidoptera: Pyralidae), is effected by male ultrasonic signals that are attractive to receptive females within 1-2 m. The males typically aggregate in the vicinity of the larval food resource, honeybee colonies, and signal for 6-10 h each night. Females are known to choose males on a relative basis and evaluate primarily three signal characters: signal rate (SR), loudness (peak amplitude; PA), and asynchrony interval (AI), a temporal feature reflecting the time interval between signals produced by the left and right tymbals. We conducted a series of experiments to investigate whether and how A. grisella males modify their signals in the presence of neighboring signalers. When separated by <40 cm, males increase their SRs by 3-6% upon perceiving a neighbor's signals, but they do not alter their PAs or Als. Increased SRs continue for 5-10 min and are more pronounced in males that are silent at the time they perceive their neighbor. By increasing its SR, a male improves the likelihood of matching or exceeding its neighbor's SR and may thereby compete more effectively for local females. SR increases are energetically demanding, though, and their brief duration and occurrence primarily at the beginning of signaling bouts may be the most prudent allocation of a male's limited energy reserves. [ABSTRACT FROM AUTHOR]

Models of perceived affective quality of soundscapes have been recently included into standards to guide the measurement and improvement of urban soundscapes. Such models have been developed in outdoor contexts and their validity in indoor built environments is unclear. A laboratory listening test was performed in a mock-up living room with a window sight, in order to develop an indoor soundscape model for residential buildings. During the test, 35 participants were asked to rate 20 different scenarios each. Scenarios were defined by combining four indoor sound sources and five urban environments, filtered through a window ajar, on 97 attribute scales. By applying principal component analysis, Comfort , Content, and Familiarity , were extracted as the main perceptual dimensions explaining respectively 58%, 25% and 7% of the total variance. Relationships between the principal component scores, acoustic parameters and indoor and outdoor sound categories were investigated. Comfort , Content, and Familiarity were found to be better predicted respectively by loudness N 10 , level variability L A10 -L A90 and sharpness S. The magnitude of linear-mixed-effect model predictions sensibly improved by accounting for sound categories, thus pointing at the importance of semantic meaning of sounds in indoor soundscape assessment. A measurement system is proposed, based on a 2-D space defined by two orthogonal axes, Comfort and Content , and two additional axes, Engagement and Privacy – Control , rotated 45° on the same plane. The model indicates the perceptual constructs to be measured (e.g. in post-occupancy evaluations), the attribute scales to be employed and actions to improve indoor soundscape quality, thus providing a reference for both research and practice. • Laboratory listening tests reproduced indoor soundscapes in living rooms. • Comfort , Content and Familiarity are the main dimensions of acoustic perception. • Privacy-Control and Engagement are at a 45° rotation from Comfort and Content. • Sound categories are fundamental predictors of indoor soundscape quality. [ABSTRACT FROM AUTHOR]