38 results on '"Earl E. Johnson"'
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2. Hearing aid fitting and developmental outcomes of children fit according to either the NAL or DSL prescription: fit-to-target, audibility, speech and language abilities
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Teresa Y. C. Ching, Vicky W. Zhang, Karen McGhie, Earl E. Johnson, Laura Button, Lauren Burns, Patricia Van Buynder, Christopher Flynn, and Sanna Hou
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Male ,Hearing aid ,Time Factors ,medicine.medical_treatment ,Child Behavior ,Neuropsychological Tests ,Audiology ,01 natural sciences ,Language and Linguistics ,law.invention ,Hearing Aids ,0302 clinical medicine ,Hearing ,Speech Production Measurement ,Randomized controlled trial ,law ,Child ,030223 otorhinolaryngology ,010301 acoustics ,education.field_of_study ,Speech Reception Threshold Test ,Age Factors ,Equipment Design ,Disabled Children ,Treatment Outcome ,Child, Preschool ,Speech Perception ,Female ,medicine.symptom ,Psychology ,High input ,Child Language ,Linguistics and Language ,medicine.medical_specialty ,Adolescent ,Hearing loss ,Population ,Article ,Hearing Loss, Bilateral ,03 medical and health sciences ,Speech and Hearing ,0103 physical sciences ,medicine ,Humans ,Correction of Hearing Impairment ,Medical prescription ,education ,Speech Intelligibility ,Significant difference ,Australia ,Auditory Threshold ,Persons With Hearing Impairments ,Digital subscriber line ,Acoustic Stimulation ,Adolescent Behavior - Abstract
OBJECTIVE: This study examined the influence of prescription on hearing aid (HA) fitting characteristics and 5-year developmental outcomes of children. DESIGN: A randomised controlled trial implemented as part of a population-based study on Longitudinal Outcomes of Children with Hearing Impairment (LOCHI). STUDY SAMPLE: Two-hundred and thirty-two children that were fit according to either the NAL or DSL prescription. RESULTS: Deviation from targets and root-mean-square (rms) error in HA fitting revealed no significant difference between fitting prescriptions. Aided audibility quantified by using the Speech Intelligibility Index (SII) model showed that DSL provided higher audibility than NAL at low and medium input levels but not at high input level. After allowing for hearing loss desensitization, differences in audibility between prescription groups were significant only at low input level. The randomised trial of prescription that was implemented for 163 children revealed no significant between-group differences in speech production, perception, and language; but parent-rated functional performance was higher for the DSL than for the NAL group. CONCLUSIONS: Proximity to prescriptive targets were similar between fitting prescriptions. The randomised trial revealed differences in aided audibility at low input level between prescription groups, but no significant differences in speech and language abilities. more...
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- 2017
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3. Comparing NAL-NL1 and DSL v5 in Hearing Aids Fit to Children with Severe or Profound Hearing Loss: Goodness of Fit-to-Targets, Impacts on Predicted Loudness and Speech Intelligibility
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Mridula Sharma, Teresa Y. C. Ching, Philip Newall, Earl E. Johnson, and Tian Kar Quar
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Male ,Hearing aid ,medicine.medical_specialty ,Adolescent ,Hearing loss ,Loudness Perception ,medicine.medical_treatment ,Intelligibility (communication) ,Audiology ,Loudness ,Speech and Hearing ,Hearing Aids ,Audiometry ,Goodness of fit ,Prosthesis Fitting ,otorhinolaryngologic diseases ,medicine ,Humans ,Child ,Hearing Loss ,medicine.diagnostic_test ,business.industry ,Equipment Design ,Audiogram ,Digital subscriber line ,Speech Perception ,Female ,medicine.symptom ,business - Abstract
Background: An important goal of providing amplification to children with hearing loss is to ensure that hearing aids are adjusted to match targets of prescriptive procedures as closely as possible. The Desired Sensation Level (DSL) v5 and the National Acoustic Laboratories’ prescription for nonlinear hearing aids, version 1 (NAL-NL1) procedures are widely used in fitting hearing aids to children. Little is known about hearing aid fitting outcomes for children with severe or profound hearing loss. Purpose: The purpose of this study was to investigate the prescribed and measured gain of hearing aids fit according to the NAL-NL1 and the DSL v5 procedure for children with moderately severe to profound hearing loss; and to examine the impact of choice of prescription on predicted speech intelligibility and loudness. Research Design: Participants were fit with Phonak Naida V SP hearing aids according to the NAL-NL1 and DSL v5 procedures. The Speech Intelligibility Index (SII) and estimated loudness were calculated using published models. Study Sample: The sample consisted of 16 children (30 ears) aged between 7 and 17 yr old. Data Collection and Analysis: The measured hearing aid gains were compared with the prescribed gains at 50 (low), 65 (medium), and 80 dB SPL (high) input levels. The goodness of fit-to-targets was quantified by calculating the average root-mean-square (RMS) error of the measured gain compared with prescriptive gain targets for 0.5, 1, 2, and 4 kHz. The significance of difference between prescriptions for hearing aid gains, SII, and loudness was examined by performing analyses of variance. Correlation analyses were used to examine the relationship between measures. Results: The DSL v5 prescribed significantly higher overall gain than the NAL-NL1 procedure for the same audiograms. For low and medium input levels, the hearing aids of all children fit with NAL-NL1 were within 5 dB RMS of prescribed targets, but 33% (10 ears) deviated from the DSL v5 targets by more than 5 dB RMS on average. For high input level, the hearing aid fittings of 60% and 43% of ears deviated by more than 5 dB RMS from targets of NAL-NL1 and DSL v5, respectively. Greater deviations from targets were associated with more severe hearing loss. On average, the SII was higher for DSL v5 than for NAL-NL1 at low input level. No significant difference in SII was found between prescriptions at medium or high input level, despite greater loudness for DSL v5 than for NAL-NL1. Conclusions: Although targets between 0.25 and 2 kHz were well matched for both prescriptions in commercial hearing aids, gain targets at 4 kHz were matched for NAL-NL1 only. Although the two prescriptions differ markedly in estimated loudness, they resulted in comparable predicted speech intelligibility for medium and high input levels. more...
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- 2015
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4. Safety limit warning levels for the avoidance of excessive sound amplification to protect against further hearing loss
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Earl E. Johnson
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Hearing aid ,Linguistics and Language ,medicine.medical_specialty ,Time Factors ,Hearing loss ,medicine.medical_treatment ,Loudness Perception ,Audiology ,Persons With Hearing Impairments ,01 natural sciences ,Risk Assessment ,Language and Linguistics ,Loudness ,03 medical and health sciences ,Speech and Hearing ,0302 clinical medicine ,Hearing Aids ,Hearing ,0103 physical sciences ,medicine ,Pressure ,Humans ,Auditory Fatigue ,030223 otorhinolaryngology ,Sound pressure ,010301 acoustics ,business.industry ,Audiogram ,Acoustics ,Equipment Design ,Models, Theoretical ,Hearing Loss, Noise-Induced ,Multivariate Analysis ,Speech Perception ,Patient Safety ,medicine.symptom ,business ,Audiometry, Speech ,Noise ,Auditory fatigue ,Sensitivity (electronics) - Abstract
To determine safe output sound pressure levels (SPL) for sound amplification devices to preserve hearing sensitivity after usage.A mathematical model consisting of the Modified Power Law (MPL) (HumesJesteadt, 1991 ) combined with equations for predicting temporary threshold shift (TTS) and subsequent permanent threshold shift (PTS) (Macrae, 1994b ) was used to determine safe output SPL.The study involves no new human subject measurements of loudness tolerance or threshold shifts. PTS was determined by the MPL model for 234 audiograms and the SPL output recommended by four different validated prescription recommendations for hearing aids.PTS can, on rare occasion, occur as a result of SPL delivered by hearing aids at modern day prescription recommendations. The trading relationship of safe output SPL, decibel hearing level (dB HL) threshold, and PTS was captured with algebraic expressions. Better hearing thresholds lowered the safe output SPL and higher thresholds raised the safe output SPL.Safe output SPL can consider the magnitude of unaided hearing loss. For devices not set to prescriptive levels, limiting the output SPL below the safe levels identified should protect against threshold worsening as a result of long-term usage. more...
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- 2017
5. Essentials of modern hearing aids: selection, fitting, and verification
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Earl E. Johnson
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Linguistics and Language ,medicine.medical_specialty ,Computer science ,business.industry ,Audiology ,medicine.disease ,computer.software_genre ,Language and Linguistics ,Test (assessment) ,Speech and Hearing ,Acquired immunodeficiency syndrome (AIDS) ,medicine ,Artificial intelligence ,business ,computer ,Selection (genetic algorithm) ,Natural language processing - Abstract
A text for the ages is how one can describe “Essentials of Modern Hearing Aids”. For one, the book is sure to stand a certain test of time. But more so, it is described as such, because the book is... more...
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- 2019
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6. Hearing-aid safety: A comparison of estimated threshold shifts for gains recommended by NAL-NL2 and DSL m[i/o] prescriptions for children
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Earl E. Johnson, Teresa Y. C. Ching, Mark Seeto, and John H. Macrae
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Hearing aid ,Linguistics and Language ,medicine.medical_specialty ,Hearing loss ,medicine.medical_treatment ,Audiology ,Article ,Language and Linguistics ,Speech and Hearing ,Threshold shift ,Hearing Aids ,medicine ,Humans ,Medical prescription ,Randomized Controlled Trials as Topic ,business.industry ,Infant ,Auditory Threshold ,Audiogram ,Models, Theoretical ,Digital subscriber line ,Hearing Loss, Noise-Induced ,Hearing level ,Child, Preschool ,medicine.symptom ,business ,Auditory fatigue - Abstract
To investigate the predicted threshold shift associated with the use of nonlinear hearing aids fitted to the NAL-NL2 or the DSL m[i/o] prescription for children with the same audiograms. For medium and high input levels, we asked: (1) How does predicted asymptotic threshold shifts (ATS) differ according to the choice of prescription? (2) How does predicted ATS vary with hearing level for gains prescribed by the two prescriptions?A mathematical model consisting of the modified power law combined with equations for predicting temporary threshold shift (Macrae, 1994b) was used to predict ATS.Predicted threshold shift were determined for 57 audiograms at medium and high input levels.For the 57 audiograms, DSL m[i/o] gains for high input levels were associated with increased risk relative to NAL-NL2. The variation of ATS with hearing level suggests that NAL-NL2 gains became unsafe when hearing loss90 dB HL. The gains prescribed by DSL m[i/o] became unsafe when hearing loss80 dB HL at a medium input level, and70 dB HL at a high input level.There is a risk of damage to hearing for children using nonlinear amplification. Vigilant checking for threshold shift is recommended. more...
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- 2013
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7. Modern Prescription Theory and Application: Realistic Expectations for Speech Recognition With Hearing Aids
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Earl E. Johnson
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Adult ,Hearing aid ,medicine.medical_specialty ,Speech perception ,Hearing Loss, Sensorineural ,Loudness Perception ,Speech recognition ,medicine.medical_treatment ,Context (language use) ,Audiology ,Loudness ,Speech and Hearing ,Hearing Aids ,Prosthesis Fitting ,otorhinolaryngologic diseases ,medicine ,Humans ,Expected return ,Medical prescription ,Sound pressure ,Aged ,Efficient frontier ,Auditory Threshold ,Equipment Design ,Articles ,Middle Aged ,Models, Theoretical ,Child, Preschool ,Speech Discrimination Tests ,Speech Perception ,Psychology - Abstract
A major decision at the time of hearing aid fitting and dispensing is the amount of amplification to provide listeners (both adult and pediatric populations) for the appropriate compensation of sensorineural hearing impairment across a range of frequencies (e.g., 160–10000 Hz) and input levels (e.g., 50–75 dB sound pressure level). This article describes modern prescription theory for hearing aids within the context of a risk versus return trade-off and efficient frontier analyses. The expected return of amplification recommendations (i.e., generic prescriptions such as National Acoustic Laboratories—Non-Linear 2, NAL-NL2, and Desired Sensation Level Multiple Input/Output, DSL m[i/o]) for the Speech Intelligibility Index (SII) and high-frequency audibility were traded against a potential risk (i.e., loudness). The modeled performance of each prescription was compared one with another and with the efficient frontier of normal hearing sensitivity (i.e., a reference point for the most return with the least risk). For the pediatric population, NAL-NL2 was more efficient for SII, while DSL m[i/o] was more efficient for high-frequency audibility. For the adult population, NAL-NL2 was more efficient for SII, while the two prescriptions were similar with regard to high-frequency audibility. In terms of absolute return (i.e., not considering the risk of loudness), however, DSL m[i/o] prescribed more outright high-frequency audibility than NAL-NL2 for either aged population, particularly, as hearing loss increased. Given the principles and demonstrated accuracy of desensitization (reduced utility of audibility with increasing hearing loss) observed at the group level, additional high-frequency audibility beyond that of NAL-NL2 is not expected to make further contributions to speech intelligibility (recognition) for the average listener. more...
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- 2013
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8. Prescriptive Amplification Recommendations for Hearing Losses with a Conductive Component and Their Impact on the Required Maximum Power Output: An Update with Accompanying Clinical Explanation
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Earl E. Johnson
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Hearing aid ,medicine.medical_specialty ,Maximum power principle ,Computer science ,Hearing loss ,Hearing Loss, Sensorineural ,medicine.medical_treatment ,Hearing Loss, Conductive ,Audiology ,Prosthesis Design ,Models, Biological ,Speech and Hearing ,Hearing Aids ,Bone conduction ,Audiometry ,Prosthesis Fitting ,otorhinolaryngologic diseases ,medicine ,Humans ,Correction of Hearing Impairment ,medicine.diagnostic_test ,Auditory Threshold ,medicine.disease ,Conductive hearing loss ,Sensorineural hearing loss ,medicine.symptom ,Insertion gain - Abstract
Background: Hearing aid prescriptive recommendations for hearing losses having a conductive component have received less clinical and research interest than for losses of a sensorineural nature; as a result, much variation remains among current prescriptive methods in their recommendations for conductive and mixed hearing losses (Johnson and Dillon, 2011). Purpose: The primary intent of this brief clinical note is to demonstrate differences between two algebraically equivalent expressions of hearing loss, which have been approaches used historically to generate a prescription for hearing losses with a conductive component. When air and bone conduction thresholds are entered into hearing aid prescriptions designed for nonlinear hearing aids, it was hypothesized that that two expressions would not yield equivalent amounts of prescribed insertion gain and output. These differences are examined for their impact on the maximum power output (MPO) requirements of the hearing aid. Subsequently, the MPO capabilities of two common behind-the-ear (BTE) receiver placement alternatives, receiver-in-aid (RIA) and receiver-in-canal (RIC), are examined. Study Samples: The two expressions of hearing losses examined were the 25% ABG + AC approach and the 75% ABG + BC approach, where ABG refers to air-bone gap, AC refers to air-conduction threshold, and BC refers to bone-conduction threshold. Example hearing loss cases with a conductive component are sampled for calculations. The MPO capabilities of the BTE receiver placements in commercially-available products were obtained from hearing aids on the U.S. federal purchasing contract. Results: Prescribed gain and the required MPO differs markedly between the two approaches. The 75% ABG + BC approach prescribes a compression ratio that is reflective of the amount of sensorineural hearing loss. Not all hearing aids will have the MPO capabilities to support the output requirements for fitting hearing losses with a large conductive component particularly when combined with significant sensorineural hearing loss. Generally, current RIA BTE products have greater output capabilities than RIC BTE products. Conclusions: The 75% ABG + BC approach is more appropriate than the 25% ABG + AC approach because the latter approach inappropriately uses AC thresholds as the basis for determining the compression ratio. That is, for hearing losses with a conductive component, the AC thresholds are not a measure of sensorineural hearing loss and cannot serve as the basis for determining the amount of desired compression. The Australian National Acoustic Laboratories has been using the 75% ABG + BC approach in lieu of the 25% ABG + AC approach since its release of the National Acoustic Laboratories—Non-linear 1 (NAL-NL1) prescriptive method in 1999. Future research may examine whether individuals with conductive hearing loss benefit or prefer more than 75% restoration of the conductive component provided adequate MPO capabilities to support such restoration. more...
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- 2013
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9. Hearing aid technology: model-based concepts and assessment
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Earl E. Johnson
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Hearing aid ,Auditory perception ,Linguistics and Language ,medicine.medical_specialty ,Third law ,Statement (logic) ,medicine.medical_treatment ,MEDLINE ,Audiology ,Language and Linguistics ,Speech and Hearing ,medicine ,Psychoacoustics ,Set (psychology) ,Psychology ,Introductory Journal Article - Abstract
“Any sufficiently advanced technology is indistinguishable from magic.” This statement made by Arthur C. Clarke is known as his third law. The developers of hearing aid technology set out to accomp... more...
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- 2017
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10. A Comparison of Gain for Adults from Generic Hearing Aid Prescriptive Methods: Impacts on Predicted Loudness, Frequency Bandwidth, and Speech Intelligibility
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Earl E. Johnson and Harvey Dillon
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Adult ,Hearing aid ,medicine.medical_specialty ,Sound Spectrography ,Speech perception ,Hearing loss ,Hearing Loss, Sensorineural ,Loudness Perception ,Speech recognition ,medicine.medical_treatment ,Audiology ,Intelligibility (communication) ,Loudness ,Speech and Hearing ,Hearing Aids ,medicine ,Humans ,Pitch Perception ,Mathematics ,medicine.diagnostic_test ,Equipment Design ,Prescriptions ,QUIET ,Speech Discrimination Tests ,Speech Perception ,Audiometry, Pure-Tone ,Audiometry ,medicine.symptom ,Perceptual Masking ,Software ,Insertion gain - Abstract
Background: Prescriptive methods have been at the core of modern hearing aid fittings for the past several decades. Every decade or so, there have been revisions to existing methods and/or the emergence of new methods that become widely used. In 2001 Byrne et al provided a comparison of insertion gain for generic prescriptive methods available at that time. Purpose: The purpose of this article was to compare National Acoustic Laboratories—Non-linear 1 (NAL-NL1), National Acoustic Laboratories—Non-linear 2 (NAL-NL2), Desired Sensation Level Multistage Input/Output (DSL m[i/o]), and Cambridge Method for Loudness Equalization 2—High-Frequency (CAMEQ2-HF) prescriptive methods for adults on the amplification characteristics of prescribed insertion gain and compression ratio. Following the differences observed in prescribed insertion gain among the four prescriptive methods, analyses of predicted specific loudness, overall loudness, and bandwidth of cochlear excitation and effective audibility as well as speech intelligibility of the international long-term average speech spectrum (ILTASS) at an average conversational input level were completed. These analyses allow for the discussion of similarities and differences among the present-day prescriptive methods. Research Design: The impact of insertion gain differences among the methods is examined for seven hypothetical hearing loss configurations using models of loudness perception and speech intelligibility. Study Sample: Hearing loss configurations for adults of various types and degrees were selected, five of which represent sensorineural impairment and were used by Byrne et al; the other two hearing losses provide an example of mixed and conductive impairment. Data Collection and Analysis: Prescribed insertion gain data were calculated in 1/3-octave frequency bands for each of the seven hearing losses from the software application of each prescriptive method over multiple input levels. The insertion gain data along with a diffuse field-to-eardrum transfer function were used to calculate output levels at the eardrums of the hypothetical listeners. Levels of hearing loss and output were then used in the Moore and Glasberg loudness model and the ANSI S3.5-1997 Speech Intelligibility Index model. Results: NAL-NL2 and DSL m[i/o] provided comparable overall loudness of approximately 8 sones for the five sensorineural hearing losses for a 65 dB SPL ILTASS input. This loudness was notably less than that perceived by a normal-hearing person for the same input signal, 18.6 sones. NAL-NL2 and DSL m[i/o] also provided comparable predicted speech intelligibility in quiet and noise. CAMEQ2-HF provided a greater average loudness, similar to NAL-NL1, with more high-frequency bandwidth but no significant improvement to predicted speech intelligibility. Conclusions: Definite variation in prescribed insertion gain was present among the prescriptive methods. These differences when averaged across the hearing losses were, by and large, negligible with regard to predicted speech intelligibility at normal conversational speech levels. With regard to loudness, DSL m[i/o] and NAL-NL2 provided the least overall loudness, followed by CAMEQ2-HF and NAL-NL1 providing the most loudness. CAMEQ2-HF provided the most audibility at high frequencies; even so, the audibility became less effective for improving speech intelligibility as hearing loss severity increased. more...
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- 2011
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11. The effect of extending high-frequency bandwidth on the Acceptable Noise Level (ANL) of hearing-impaired listeners
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Todd A. Ricketts, Earl E. Johnson, and Benjamin W. Y. Hornsby
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Hearing aid ,Linguistics and Language ,medicine.medical_specialty ,Reverberation ,Time Factors ,Computer science ,Hearing loss ,Hearing Loss, Sensorineural ,Loudness Perception ,Speech recognition ,medicine.medical_treatment ,Audiology ,Speech Acoustics ,Language and Linguistics ,Background noise ,Speech and Hearing ,otorhinolaryngologic diseases ,medicine ,Humans ,Speech ,Psychoacoustics ,medicine.diagnostic_test ,Bandwidth (signal processing) ,Acoustics ,Middle Aged ,Persons With Hearing Impairments ,Acoustic Stimulation ,Auditory Perception ,Audiometry, Pure-Tone ,Audiometry ,medicine.symptom ,Noise - Abstract
This study examined the effects of extending high-frequency bandwidth, for both a speech signal and a background noise, on the acceptable signal-to-noise ratio (SNR) of listeners with mild sensorineural hearing loss through utilization of the Acceptable Noise Level (ANL) procedure. In addition to extending high-frequency bandwidth, the effects of reverberation time and background noise type and shape were also examined. The study results showed a significant increase in the mean ANL (i.e. participants requested a better SNR for an acceptable listening situation) when high-frequency bandwidth was extended from 3 to 9 kHz and from 6 to 9 kHz. No change in the ANL of study participants was observed as a result of isolated modification to reverberation time or background noise stimulus. An interaction effect, however, of reverberation time and background noise stimulus was demonstrated. These findings may have implications for future design of hearing aid memory programs for listening to speech in the presence of broadband background noise. more...
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- 2009
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12. Statistically Derived Factors of Varied Importance to Audiologists When Making a Hearing Aid Brand Preference Decision
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H. Gustav Mueller, Earl E. Johnson, and Todd A. Ricketts
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Male ,Hearing aid ,Research design ,Brand preference ,Data Collection ,medicine.medical_treatment ,media_common.quotation_subject ,Decision Making ,Significant difference ,Audiology ,Preference ,Speech and Hearing ,Survey methodology ,Hearing Aids ,Incentive ,medicine ,Humans ,Female ,Aptitude ,Psychology ,Social psychology ,media_common - Abstract
Purpose: To determine the amount of importance audiologists place on various items related to their selection of a preferred hearing aid brand manufacturer. Research Design: Three hundred forty-three hearing aid–dispensing audiologists rated a total of 32 randomized items by survey methodology. Results: Principle component analysis identified seven orthogonal statistical factors of importance. In rank order, these factors were Aptitude of the Brand, Image, Cost, Sales and Speed of Delivery, Exposure, Colleague Recommendations, and Contracts and Incentives. While it was hypothesized that differences among audiologists in the importance ratings of these factors would dictate their preference for a given brand, that was not our finding. Specifically, mean ratings for the six most important factors did not differ among audiologists preferring different brands. A statistically significant difference among audiologists preferring different brands was present, however, for one factor: Contracts and Incentives. Its assigned importance, though, was always lower than that for the other six factors. Conclusions: Although most audiologists have a preferred hearing aid brand, differences in the perceived importance of common factors attributed to brands do not largely determine preference for a particular brand. more...
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- 2009
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13. Individual Differences within and across Feedback Suppression Hearing Aids
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Todd A. Ricketts, Jeremy Federman, and Earl E. Johnson
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Measurement method ,medicine.medical_specialty ,Gain before feedback ,Microphone ,Computer science ,Individuality ,Reproducibility of Results ,Acoustics ,Audiology ,Manikins ,Prosthesis Design ,Speech and Hearing ,Hearing Aids ,Prosthesis Fitting ,medicine ,Range (statistics) ,Humans ,Hearing Loss ,Noise - Abstract
Background: New and improved methods of feedback suppression are routinely introduced in hearing aids; however, comparisons of additional gain before feedback (AGBF) values across instruments are complicated by potential variability across subjects and measurement methods. Purpose: To examine the variability in AGBF values across individual listeners and an acoustic manikin. Research Design: A descriptive study of the reliability and variability of the AGBF measured within six commercially available feedback suppression (FS) algorithms using probe microphone techniques. Study Sample: Sixteen participants and an acoustic manikin. Results: The range of AGBF across the six FS algorithms was 0 to 15 dB, consistent with other recent studies. However, measures made in the participants ears and on the acoustic manikin within the same instrument suggest that across instrument comparisons of AGBF measured using acoustic manikin techniques may be misleading, especially when differences between hearing aids are small (i.e., less than 6 dB). Individual subject results also revealed considerable variability within the same FS algorithms. The range of AGBF values was as small as 7 dB and as large as 16 dB depending on the specific FS algorithm, suggesting that some models are much more robust than others. Conclusions: These results suggest caution when selecting FS algorithms clinically since different models can demonstrate similar AGBF when averaging across ears, but result in quite different AGBF values in a single individual ear. more...
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- 2008
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14. Practitioners give high marks for user benefit to open-canal mini-BTEs
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Earl E. Johnson
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Speech and Hearing - Published
- 2008
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15. Survey finds higher sales and prices, plus more open fittings and directional mics
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Earl E. Johnson
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Speech and Hearing ,Computer science - Published
- 2007
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16. A Patient-Centered, Provider-Facilitated Approach to the Refinement of Nonlinear Frequency Compression Parameters Based on Subjective Preference Ratings of Amplified Sound Quality
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Keri C. Light and Earl E. Johnson
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Hearing aid ,Male ,medicine.medical_specialty ,Wilcoxon signed-rank test ,medicine.medical_treatment ,Hearing Loss, Sensorineural ,Audiology ,Speech and Hearing ,Hearing Aids ,Audiometry ,medicine ,Humans ,Sound quality ,Hearing Loss, High-Frequency ,Statistic ,Aged ,Veterans ,Aged, 80 and over ,Data collection ,medicine.diagnostic_test ,Nonparametric statistics ,Patient Preference ,Equipment Design ,Middle Aged ,Preference ,United States ,Speech Perception ,Psychology - Abstract
Purpose: To evaluate sound quality preferences of participants wearing hearing aids with different strengths of nonlinear frequency compression (NFC) processing versus no NFC processing. Two analysis methods, one without and one with a qualifier as to the magnitude of preferences, were compared for their percent agreement to differentiate a small difference in perceived sound quality as a result of applied NFC processing. Research Design: A single-blind design was used with participants unaware of the presence or strength of NFC processing (independent variable). The National Acoustic Laboratories-Nonlinear 2 (NAL-NL2) prescription of amplification was chosen because audibility is intentionally not prescribed in the presence of larger sensorineural hearing loss thresholds. A lack of prescribed audibility, when present, was deemed an objective qualifier for NFC. NFC is known to improve the input bandwidth available to listeners when high-frequency audibility is not otherwise available and increasing strengths of NFC were examined. Experimental condition 3 (EC3) was stronger than the manufacturer default (EC2). More aggressive strengths (e.g., EC4 and EC5), however, were expected to include excessive distortion and even reduce the output bandwidth that had been prescribed as audible by NAL-NL2 (EC1). Study Sample: A total of 14 male Veterans with severe high-frequency sensorineural hearing loss. Data Collection and Analysis: Participant sound quality preference ratings (dependent variable) without a qualifier as to the magnitude of preference were analyzed based on binomial probability theory, as is traditional with paired comparison data. The ratings with a qualifier as to the magnitude of preference were analyzed based on the nonparametric statistic of the Wilcoxon signed rank test. Results: The binomial probability analysis method identified a sound quality preference as well as the nonparametric probability test method. As the strength of NFC increased, more participants preferred the EC with less NFC. Fourteen of 14 participants showed equal preference between EC1 and EC2 perhaps, in part, because EC2 showed no objective improvement in audibility for six of the 14 participants (42%). Thirteen of the 14 participants showed no preference between NAL-NL2 and EC3, but all participants had an objective improvement in audibility. With more NFC than EC3, more and more participants preferred the other EC with less NFC in the paired comparison. Conclusions: By referencing the recommended sensation levels of amplitude compression (e.g., NAL-NL2) in the ear canal of hearing aid wearers, the targeting of NFC parameters can likely be optimized with respect to improvements in effective audibility that may contribute to speech recognition without adversely impacting sound quality. After targeting of NFC parameters, providers can facilitate decisions about the use of NFC parameters (strengths of processing) via sound quality preference judgments using paired comparisons. more...
- Published
- 2015
17. Between the Storms: Reflections on Chaplaincy during Natural and Human-caused Disasters
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Earl E. Johnson
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History ,Environmental ethics ,Storm ,General Medicine ,Natural (archaeology) - Abstract
(2006). Between the Storms: Reflections on Chaplaincy during Natural and Human-caused Disasters. Chaplaincy Today: Vol. 22, No. 2, pp. 3-7.
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- 2006
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18. Adaptive Directional Benefit in the Near Field: Competing Sound Angle and Level Effects
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Todd A. Ricketts, Benjamin W. Y. Hornsby, and Earl E. Johnson
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Speech and Hearing ,geography ,geography.geographical_feature_category ,Computer science ,Ecology ,Acoustics ,Near and far field ,Sound (geography) - Published
- 2005
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19. OTC Hearing Aids
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Earl E. Johnson
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Speech and Hearing ,Acquired immunodeficiency syndrome (AIDS) ,business.industry ,Medicine ,Medical emergency ,business ,medicine.disease - Published
- 2018
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20. Segmenting dispensers
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Earl E. Johnson
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Speech and Hearing ,business.industry ,Medicine ,Computer vision ,Artificial intelligence ,business - Published
- 2006
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21. A comparison of NAL and DSL prescriptive methods for paediatric hearing-aid fitting: predicted speech intelligibility and loudness
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Lauren Burns, Sanna Hou, Patricia Van Buynder, Angela Wong, Earl E. Johnson, Harvey Dillon, Vicky W. Zhang, Christopher Flynn, and Teresa Y. C. Ching
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Hearing aid ,Linguistics and Language ,Loudness Perception ,medicine.medical_specialty ,Speech perception ,Speech recognition ,medicine.medical_treatment ,Audiology ,Language and Linguistics ,Article ,Loudness ,Speech and Hearing ,Hearing Aids ,medicine ,Humans ,Hearing Loss ,Mathematics ,Extramural ,Low input ,Speech Intelligibility ,Infant ,Models, Theoretical ,Digital subscriber line ,Prescriptions ,Child, Preschool ,Speech Perception ,High input - Abstract
To examine the impact of prescription on predicted speech intelligibility and loudness for children.A between-group comparison of speech intelligibility index (SII) and loudness, based on hearing aids fitted according to NAL-NL1, DSL v4.1, or DSL m[i/o] prescriptions. A within-group comparison of gains prescribed by DSL m[i/o] and NAL-NL2 for children in terms of SII and loudness.Participants were 200 children, who were randomly assigned to first hearing-aid fitting with either NAL-NL1, DSL v4.1, or DSL m[i/o]. Audiometric data and hearing-aid data at 3 years of age were used.On average, SII calculated on the basis of hearing-aid gains were higher for DSL than for NAL-NL1 at low input level, equivalent at medium input level, and higher for NAL-NL1 than DSL at high input level. Greater loudness was associated with DSL than with NAL-NL1, across a range of input levels. Comparing NAL-NL2 and DSL m[i/o] target gains revealed higher SII for the latter at low input level. SII was higher for NAL-NL2 than for DSL m[i/o] at medium- and high-input levels despite greater loudness for gains prescribed by DSL m[i/o] than by NAL-NL2.The choice of prescription has minimal effects on speech intelligibility predictions but marked effects on loudness predictions. more...
- Published
- 2013
22. An initial-fit comparison of two generic hearing aid prescriptive methods (NAL-NL2 and CAM2) to individuals having mild to moderately severe high-frequency hearing loss
- Author
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Earl E. Johnson
- Subjects
Research design ,Hearing aid ,Male ,medicine.medical_specialty ,Speech perception ,Hearing loss ,medicine.medical_treatment ,Hearing Loss, Sensorineural ,Loudness Perception ,Audiology ,Severity of Illness Index ,Loudness ,Speech and Hearing ,Hearing Aids ,Audiometry ,medicine ,Humans ,Active listening ,Single-Blind Method ,Sound quality ,Hearing Loss, High-Frequency ,Aged ,medicine.diagnostic_test ,Reproducibility of Results ,Patient Preference ,Middle Aged ,Speech Discrimination Tests ,Speech Perception ,Female ,medicine.symptom ,Psychology ,Software - Abstract
Background: Johnson and Dillon (2011) provided a model-based comparison of current generic hearing aid prescriptive methods for adults with hearing loss based on the attributes of speech intelligibility, loudness, and bandwidth. Purpose: This study compared the National Acoustic Laboratories—Non-linear 2 (NAL-NL2) and Cambridge Method for Loudness Equalization 2—High-Frequency (CAM2) prescriptive methods using adult participants with less high-frequency hearing loss than Johnson and Dillon (2011). Of study interest was quantification of prescribed audibility, speech intelligibility, and loudness. The preferences of participants for either NAL-NL2 or CAM2 and preferred deviations from prescribed settings are also reported. Research Design: Using a single-blind, counter-balanced, randomized design, preference judgments for the prescriptive methods with regard to sound quality of speech and music stimuli were obtained. Preferred gain adjustments from the prescription within the 4–10 kHz frequency range were also obtained from each participant. Speech intelligibility and loudness model calculations were completed on the prescribed and adjusted amplification. Study Sample: Fourteen male Veterans, whose average age was 65 yr and whose hearing sensitivity averaged normal to borderline normal through 1000 Hz sloping to a moderately severe sensorineural loss, served as participants. Data Collection and Analysis: Following a brief listening time (˜10 min), typical of an initial fitting visit, the participants made paired comparison of sound quality between the NAL-NL2 and CAM2 prescriptive settings. Participants were also asked to modify each prescription in the range of 4–10 kHz using an overall gain control and make subsequent comparisons of sound quality preference between prescriptive and adjusted settings. Participant preferences were examined with respect to quantitative analysis of loudness modeling, speech intelligibility modeling, and measured high-frequency bandwidth audibility. Results: Consistent with the lack of difference in predicted speech intelligibility between the two prescriptions, sound quality preferences on the basis of clarity were split across participants while some participants did not have a discernable preference. Considering sound quality judgments of pleasantness, the majority of participants preferred the sound quality of the NAL-NL2 (8 of 14) prescription instead of the CAM2 prescription (2 of 14). Four of the 14 participants showed no preference on the basis of pleasantness for either prescription. Individual subject preferences were supported by loudness modeling that indicated NAL-NL2 was the softer of the two prescriptions and CAM2 was the louder. CAM2 did provide more audibility to the higher frequencies (5–8 kHz) than NAL-NL2. Participants turned the 4–10 kHz gain recommendation of CAM2 lower, on average, by a significant amount of 4 dB when making adjustments while no significant adjustment was made to the initial NAL-NL2 recommendation. Conclusions: NAL-NL2 prescribed gains were more often preferred at the initial fitting by the majority of participating veterans. For those patients with preference for a louder fitting than NAL-NL2, CAM2 is a good alternative. When the participant adjustment from the prescription between 4 and 10 kHz exceeded 4 dB from either NAL-NL2 (2 of 14) or CAM2 (11 of 14), the participants demonstrated a later preference for that adjustment 69% of the time. These findings are viewed as limited evidence that some individuals may have a preference for high-frequency gain that differs from the starting prescription. more...
- Published
- 2013
23. Effects of degree and configuration of hearing loss on the contribution of high- and low-frequency speech information to bilateral speech understanding
- Author
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Benjamin W. Y. Hornsby, Earl E. Johnson, and Erin M. Picou
- Subjects
Adult ,Male ,medicine.medical_specialty ,Hearing loss ,Speech recognition ,Hearing Loss, Sensorineural ,Intelligibility (communication) ,Audiology ,Severity of Illness Index ,Article ,Background noise ,Speech and Hearing ,Young Adult ,Linear regression ,otorhinolaryngologic diseases ,medicine ,Humans ,Wideband ,Pitch Perception ,Mathematics ,Aged ,Aged, 80 and over ,Bandwidth (signal processing) ,Linear model ,Auditory Threshold ,Middle Aged ,medicine.disease ,Otorhinolaryngology ,Linear Models ,Speech Discrimination Tests ,Speech Perception ,Sensorineural hearing loss ,Female ,medicine.symptom ,Noise ,Follow-Up Studies - Abstract
Objectives The purpose of this study was to examine the effects of degree and configuration of hearing loss on the use of, and benefit from, information in amplified high- and low-frequency speech presented in background noise. Design Sixty-two adults with a wide range of high- and low-frequency sensorineural hearing loss (5 to 115+ dB HL) participated in the study. To examine the contribution of speech information in different frequency regions, speech understanding in noise was assessed in multiple low- and high-pass filter conditions, as well as a band-pass (713 to 3534 Hz) and wideband (143 to 8976 Hz) condition. To increase audibility over a wide frequency range, speech and noise were amplified based on each individual's hearing loss. A stepwise multiple linear regression approach was used to examine the contribution of several factors to (1) absolute performance in each filter condition and (2) the change in performance with the addition of amplified high- and low-frequency speech components. Results Results from the regression analysis showed that degree of hearing loss was the strongest predictor of absolute performance for low- and high-pass filtered speech materials. In addition, configuration of hearing loss affected both absolute performance for severely low-pass filtered speech and benefit from extending high-frequency (3534 to 8976 Hz) bandwidth. Specifically, individuals with steeply sloping high-frequency losses made better use of low-pass filtered speech information than individuals with similar low-frequency thresholds but less high-frequency loss. In contrast, given similar high-frequency thresholds, individuals with flat hearing losses received more benefit from extending high-frequency bandwidth than individuals with more sloping losses. Conclusions Consistent with previous work, benefit from speech information in a given frequency region generally decreases as degree of hearing loss in that frequency region increases. However, given a similar degree of loss, the configuration of hearing loss also affects the ability to use speech information in different frequency regions. Except for individuals with steeply sloping high-frequency losses, providing high-frequency amplification (3534 to 8976 Hz) had either a beneficial effect on, or did not significantly degrade, speech understanding. These findings highlight the importance of extended high-frequency amplification for listeners with a wide range of high-frequency hearing losses, when seeking to maximize intelligibility. more...
- Published
- 2011
24. Dispensing rates of four common hearing aid product features: associations with variations in practice among audiologists
- Author
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Todd A. Ricketts and Earl E. Johnson
- Subjects
Hearing aid ,Adult ,Male ,medicine.medical_specialty ,Health Knowledge, Attitudes, Practice ,Time Factors ,Adolescent ,Attitude of Health Personnel ,medicine.medical_treatment ,Audiologist ,Audiology ,Choice Behavior ,Article ,Speech and Hearing ,Young Adult ,Hearing Aids ,Surveys and Questionnaires ,medicine ,Feature (machine learning) ,Humans ,Product (category theory) ,Child ,Workplace ,Aged ,Aged, 80 and over ,Evidence-Based Medicine ,Guideline adherence ,business.industry ,Infant ,Regression analysis ,Professional Practice ,Evidence-based medicine ,Equipment Design ,Middle Aged ,United States ,Patient population ,Child, Preschool ,Health Care Surveys ,Practice Guidelines as Topic ,Educational Status ,Regression Analysis ,Female ,Guideline Adherence ,business ,Factor Analysis, Statistical - Abstract
The purpose of the study was to develop and examine a list of potential variables that may account for variability in the dispensing rates of four common hearing aid features. A total of 29 potential variables were identified and placed into the following categories: (1) characteristics of the audiologist, (2) characteristics of the hearing aids dispensed by the audiologist, (3) characteristics of the audiologist’s patient population, and (4) evidence-based practice grades of recommendation for each feature. The potentially associative variables then were examined using regression analyses from the responses of 257 audiologists to a dispensing practice survey. There was a direct relation between price and level of hearing aid technology with the frequency of dispensing product features. There was also a direct relation between the belief by the audiologist that a feature might benefit patients and the frequency of dispensing that feature. In general, the results suggested that personal differences among audiologists and the hearing aids audiologists choose to dispense are related more strongly to dispensing rates of product features than to differences in characteristics of the patient population served by audiologists. An additional finding indicated that evidence-based practice recommendations were inversely related to dispensing rates of product features. This finding, however, may not be the result of dispensing trends as much as hearing aid manufacturing trends. more...
- Published
- 2010
25. High-frequency amplification and sound quality in listeners with normal through moderate hearing loss
- Author
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Earl E. Johnson, Todd A. Ricketts, and Andrew B. Dittberner
- Subjects
Adult ,Male ,Linguistics and Language ,medicine.medical_specialty ,Speech perception ,Hearing loss ,Acoustics ,Audiology ,Severity of Illness Index ,Language and Linguistics ,Speech and Hearing ,Hearing Aids ,Hearing ,Assistive technology ,medicine ,Humans ,Sound quality ,Hearing Loss, High-Frequency ,Mathematics ,Aged ,medicine.diagnostic_test ,Pure tone ,Bandwidth (signal processing) ,Middle Aged ,Acoustic Stimulation ,Patient Satisfaction ,Speech Perception ,Audiometry, Pure-Tone ,Female ,Audiometry ,medicine.symptom ,Music - Abstract
Purpose One factor that has been shown to greatly affect sound quality is audible bandwidth. Provision of gain for frequencies above 4–6 kHz has not generally been supported for groups of hearing aid wearers. The purpose of this study was to determine if preference for bandwidth extension in hearing aid processed sounds was related to the magnitude of hearing loss in individual listeners. Method Ten participants with normal hearing and 20 participants with mild-to-moderate hearing loss completed the study. Signals were processed using hearing aid–style compression algorithms and filtered using two cutoff frequencies, 5.5 and 9 kHz, which were selected to represent bandwidths that are achievable in modern hearing aids. Round-robin paired comparisons based on the criteria of preferred sound quality were made for 2 different monaurally presented brief sound segments, including music and a movie. Results Results revealed that preference for either the wider or narrower bandwidth (9- or 5.5-kHz cutoff frequency, respectively) was correlated with the slope of hearing loss from 4 to 12 kHz, with steep threshold slopes associated with preference for narrower bandwidths. Conclusion Consistent preference for wider bandwidth is present in some listeners with mild-to-moderate hearing loss. more...
- Published
- 2008
26. The effect of digital phase cancellation feedback reduction systems on amplified sound quality
- Author
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Benjamin W. Y. Hornsby, Earl E. Johnson, and Todd A. Ricketts
- Subjects
Hearing aid ,Phase cancellation ,medicine.medical_specialty ,Wilcoxon signed-rank test ,Computer science ,Hearing loss ,medicine.medical_treatment ,Speech recognition ,Paired comparison ,Audiology ,Reduction (complexity) ,Speech and Hearing ,Hearing Aids ,Phonetics ,medicine ,Humans ,Sound quality ,Hearing Loss ,Aged ,Quality of Health Care ,Aged, 80 and over ,Middle Aged ,Acoustic Stimulation ,Patient Satisfaction ,medicine.symptom ,Music - Abstract
The effect of feedback reduction (FBR) systems on sound quality recorded from two commercially available hearing aids was evaluated using paired comparison judgments by 16 participants with mild to severe sloping hearing loss. These comparisons were made with the FBR systems on and off without audible feedback and while attempting to control for differences in gain and clinical fitting factors. Wilcoxon signed rank test analyses showed that the participants were unable to differentiate between signals that had been recorded with the FBR systems on and off within the same hearing aid. However, significant between-instrument differences in sound quality were identified. The results support the activation of the FFT-phase cancellation FBR systems evaluated herein without concern for a noticeable degradation of sound quality. Se evaluó el efecto de los sistemas de reducción de la retroalimentaciñn (FBR) sobre la calidad del sonido registrado por medio de dos auxiliaries auditivos disponibles comercialmente, utilizando juicios de comparación en pares, de 16 participantes con una hipocusia leve a moderada de pendiente pronunciada. Estas comparaciones se realizaron con los sistemas FBR apagados y encendidos, sin retroalimentación audible y tratando de controlar las diferencias en cuanto a ganancia y a factores clínicos de adaptación. Los análisis de pruebas de rango certificados por Wilcoxon mostraron que los participantes no podian diferenciar entre señales que habian sido registradas con los sistemas de FBR encendidos o apagados dentro del mismo auxiliar auditivo. Los resultados apoyan la activación de los sistemas de FBR de cancelación de fase FFT, aqui evaluados, sin preocupaciones por una degradación identificable en la calidad del sonido. more...
- Published
- 2007
27. This is about difference
- Author
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Earl E, Johnson
- Subjects
Humans ,Pastoral Care ,Prejudice ,United States - Published
- 2006
28. The effects of speech and speechlike maskers on unaided and aided speech recognition in persons with hearing loss
- Author
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Benjamin W. Y. Hornsby, Earl E. Johnson, and Todd A. Ricketts
- Subjects
Conversational speech ,Adult ,Male ,medicine.medical_specialty ,Speech perception ,Computer science ,Hearing loss ,Speech recognition ,Perceptual Masking ,Audiology ,Background noise ,Speech and Hearing ,Hearing Aids ,otorhinolaryngologic diseases ,medicine ,Humans ,Hearing Loss ,medicine.diagnostic_test ,Middle Aged ,Noise ,Informational masking ,Treatment Outcome ,Case-Control Studies ,Speech Perception ,Audiometry, Pure-Tone ,Female ,Audiometry ,medicine.symptom - Abstract
Speech understanding in noise is affected by both the energetic and informational masking components of the background noise. In addition, when the background noise is everyday speech, the relative contributions of the energetic and informational masking components to the overall difficulties in understanding speech are unclear. This study estimated informational masking effects, in conversational speech settings, on the speech understanding of persons with and without hearing loss. The benefits and limitations of amplification in settings containing both informational and energetic masking components were also explored. Speech recognition was assessed in the presence of two types of maskers (speech and noise) that varied in the amount of informational masking they were expected to produce. Persons with hearing loss were tested both unaided and aided. Study results suggest that background noise, consisting of individual talkers, results in both informational and energetic masking. In addition, the benefits of amplification are limited when the background noise contains both informational and energetic masking components. more...
- Published
- 2006
29. Survey explores how dispensers use and choose their preferred hearing aid brands
- Author
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Earl E. Johnson
- Subjects
Hearing aid ,Speech and Hearing ,medicine.medical_specialty ,medicine.medical_treatment ,medicine ,Audiology ,Psychology - Published
- 2007
- Full Text
- View/download PDF
30. Despite having more advanced features, hearing aids hold line on retail price
- Author
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Earl E. Johnson
- Subjects
Speech and Hearing ,Acquired immunodeficiency syndrome (AIDS) ,Computer science ,medicine ,Optometry ,Line (text file) ,medicine.disease - Published
- 2008
- Full Text
- View/download PDF
31. A Response Letter to the McCreery et al (2016) Article "Stability of Audiometric Thresholds for Children with Hearing Aids Applying the American Academy of Audiology Pediatric Amplification Guideline: Implications for Safety".
- Author
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Johnson E
- Subjects
- Academies and Institutes, Audiometry, Child, Hearing Loss, Humans, United States, Audiology, Hearing Aids
- Published
- 2016
- Full Text
- View/download PDF
32. Predicting tooth-size discrepancy: A new formula utilizing revised landmarks and 3-dimensional laser scanning technology.
- Author
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Bailey E, Nelson G, Miller AJ, Andrews L, and Johnson E
- Subjects
- Bicuspid anatomy & histology, Cuspid anatomy & histology, Dental Arch anatomy & histology, Forecasting, Holography, Humans, Image Processing, Computer-Assisted methods, Incisor anatomy & histology, Mandible anatomy & histology, Maxilla anatomy & histology, Models, Dental, Molar anatomy & histology, Retrospective Studies, Tooth Crown anatomy & histology, User-Computer Interface, Anatomic Landmarks anatomy & histology, Imaging, Three-Dimensional methods, Lasers, Odontometry methods, Tooth anatomy & histology
- Abstract
Introduction: The goal of this study was to develop a more accurate formula to forecast tooth-size discrepancies in patients based on not only the size of the whole teeth but also functional arch components derived from normal cusp-fossa interdigitation that should be obtained as the final treatment goal., Methods: A total of 141 dental casts from Dr Larry Andrews' collection of "normal occlusions" that never received orthodontic treatment were scanned with an Ortho Insight 3D Laser Scanner (Motion View Software, Chattanooga, Tenn). Individual tooth sizes and portions of tooth sizes were measured with the Motion View Software. For each set of models, potential tooth-size discrepancies were calculated by using both the original Bolton analysis and the new Johnson/Bailey analysis developed by this team at the University of California at San Francisco (UCSF). Six tooth-size discrepancy ratios were computed and included the Bolton (2) and the new (4) Johnson/Bailey analysis ratios for the anterior arch component, posterior arch component, and overall ratio of the maxillary and mandibular arches. The Johnson/Bailey analysis utilized different landmarks and groups of teeth. It consequently divided the maxillary segment by the mandibular segment, in contrast to the Bolton ratios, which divided the mandibular sums by the maxillary totals., Results: The Bolton anterior segment ratio ranged from 70.68 to 84.81, with a mean of 77.91 (SD, 2.43) (3.1%). The Bolton overall ratio ranged from 86.19 to 96.62, with a mean of 91.64 (SD, ±1.74) (1.8%). The Johnson/Bailey posterior discrepancy ratio ranged from 0.98 to 1.23, with a mean of 1.10 (SD, ±0.04) (3.6%). Its anterior discrepancy ratio ranged from 0.91 to 1.14, with a mean of 1.03 (SD, ±0.04) (3.9%). The Johnson/Bailey overall discrepancy ratio ranged from 0.98 to 1.15, with a mean of 1.06 (SD, ±0.03) (2.8%)., Conclusions: Two methods were used to forecast tooth-size discrepancies between opposing arches in a sample with clinically acceptable occlusions. The new approach provided more specific ratios utilizing more clinically relevant functional arch components derived from dental cusp-fossa interdigitation., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...
- Published
- 2013
- Full Text
- View/download PDF
33. Selecting custom torque prescriptions for the straight-wire appliance.
- Author
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Johnson E
- Subjects
- Dental Alloys, Humans, Orthodontic Brackets, Torque, Dental Stress Analysis, Orthodontic Appliance Design, Orthodontic Wires, Orthodontics, Corrective methods
- Abstract
Selecting custom torque prescriptions based on the treatment needs of each patient can reduce the amount of routine archwire torque adjustment needed and speed torque correction, thus reducing the total treatment time. Using the appropriate torque prescription prevents iatrogenic torque problems and allows most torque corrections to be done earlier with more resilient nickel-titanium and beta-titanium wires. As a result, fewer time-consuming final torque adjustments are needed with stainless steel finishing wires, resulting in shorter treatment time., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...
- Published
- 2013
- Full Text
- View/download PDF
34. Managing second molars.
- Author
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Johnson E
- Subjects
- Humans, Mandible, Maxilla, Molar, Third surgery, Orthodontic Wires, Tooth Movement Techniques instrumentation, Torque, Mesial Movement of Teeth therapy, Molar pathology, Tooth Movement Techniques methods, Tooth, Impacted therapy
- Abstract
Second molars can create great delays in orthodontic treatment if they are not managed intelligently. The purpose of this article was to describe common torque and position problems of the second molars and techniques for managing them. A simple technique for freeing mesially impacted second molars is presented., (Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...
- Published
- 2011
- Full Text
- View/download PDF
35. The role of calcium in the activation of estrogen receptor-alpha.
- Author
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Divekar SD, Storchan GB, Sperle K, Veselik DJ, Johnson E, Dakshanamurthy S, Lajiminmuhip YN, Nakles RE, Huang L, and Martin MB
- Subjects
- Cell Line, Tumor, Female, Gene Expression Regulation physiology, Humans, Immunoprecipitation, Mutagenesis, Site-Directed, Protein Structure, Tertiary, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction physiology, Breast Neoplasms metabolism, Calcium metabolism, Estrogen Receptor alpha metabolism, Receptor Cross-Talk physiology
- Abstract
Environmental estrogen mimics, including metalloestrogens that can activate estrogen receptor-alpha (ERα), may contribute to breast cancer risk. However, the underlying mechanisms through which these molecular mimics activate the ERα are generally poorly understood. With concern to this important question, we investigated whether intracellular calcium may mediate the cross-talk between signaling pathways that activate ERα and the ligand-binding domain of ERα. MCF-7 cells treated with EGF, ATP, extracellular calcium, or caffeine to increase intracellular calcium triggered a rapid recruitment of ERα to estrogen-responsive promoters and stimulated expression of estrogen-responsive genes including pS2, complement C3, and progesterone receptor. Induction was blocked by an antiestrogen but also by the chelation of intracellular calcium. Treatment with extracellular calcium also increased the growth of MCF-7 cells through an ER-dependent mechanism. We found that EGF and extracellular calcium activated the C-terminus of ERα and the activation was blocked by the antiestrogen. Mechanistic investigations identified four potential sites on the solvent-accessible surface of the ERα ligand-binding domain as important for calcium activation of the receptor. Taken together, our results suggest that calcium mediates the cross-talk between ERα-activating signaling pathways and the ligand-binding domain of ERα providing a potential explanation for the ability of certain environmental metalloestrogens to activate the receptor., (©2011 AACR.) more...
- Published
- 2011
- Full Text
- View/download PDF
36. Comparative analysis of traditional radiographs and cone-beam computed tomography volumetric images in the diagnosis and treatment planning of maxillary impacted canines.
- Author
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Haney E, Gansky SA, Lee JS, Johnson E, Maki K, Miller AJ, and Huang JC
- Subjects
- Adolescent, Adult, Child, Female, Humans, Image Processing, Computer-Assisted statistics & numerical data, Imaging, Three-Dimensional statistics & numerical data, Male, Observer Variation, Prospective Studies, Radiography, Bitewing statistics & numerical data, Radiography, Panoramic statistics & numerical data, Root Resorption diagnostic imaging, Tooth Crown diagnostic imaging, Tooth Extraction statistics & numerical data, Tooth Movement Techniques statistics & numerical data, Young Adult, Cone-Beam Computed Tomography statistics & numerical data, Cuspid diagnostic imaging, Maxilla diagnostic imaging, Patient Care Planning, Radiography, Dental statistics & numerical data, Tooth, Impacted diagnostic imaging
- Abstract
Introduction: In this prospective study, we compared differences in the diagnosis and treatment planning of impacted maxillary canines between 2 imaging modalities., Methods: Twenty-five consecutive impacted maxillary canines were identified from the pool of patients seeking orthodontic treatment. The first set of radiographs consisted of traditional 2-dimensional (2D) images including panoramic, occlusal, and 2 periapical radiographs. The second set comprised prints of 3-dimensional (3D) volumetric dentition images obtained from a cone-beam computed tomography (CBCT) scan. Seven faculty member completed a questionnaire for every impacted canine and diagnostic radiographic modality (2D and 3D)., Results: The data show that the judges produced different decisions regarding localization depending on the x-ray method. There were 21% disagreement (or discordance) in the perceived mesiodistal cusp tip position and 16% difference in the perceived labiopalatal position. In the perception of root resorption of adjacent teeth, there was 36% lack of congruence. Twenty-seven percent of the teeth that were planned to be left, recovered, or extracted with the 2D radiographs had different treatment plans when the judges viewed the 3D CBCT images (McNemar test, chi-square, 4.45; P = 0.035). The clinicians' confidence of the accuracy of diagnosis and treatment plan was statistically higher for CBCT images (P <0.001)., Conclusions: These results showed that 2D and 3D images of impacted maxillary canines can produce different diagnoses and treatment plans., (Copyright (c) 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...
- Published
- 2010
- Full Text
- View/download PDF
37. Local recurrence of ductal carcinoma in situ after skin-sparing mastectomy.
- Author
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Carlson GW, Page A, Johnson E, Nicholson K, Styblo TM, and Wood WC
- Subjects
- Adult, Carcinoma in Situ pathology, Carcinoma, Ductal, Breast pathology, Chi-Square Distribution, Female, Humans, Incidence, Middle Aged, Neoplasm Recurrence, Local epidemiology, Retrospective Studies, Risk Factors, Breast Neoplasms pathology, Breast Neoplasms surgery, Carcinoma in Situ surgery, Carcinoma, Ductal, Breast surgery, Mastectomy methods
- Abstract
Background: The incidence of local recurrence (LR) after conventional total mastectomy for ductal carcinoma in situ (DCIS) ranges from 1% to 3%. Skin-sparing mastectomy (SSM) preserves the native skin envelope to facilitate immediate breast reconstruction. Because DCIS is generally not clinically apparent, there is a potential for inadequate excision when SSM is performed. Risk factors for local recurrence after SSM for DCIS are examined., Study Design: A retrospective review of 223 consecutive patients with DCIS treated by SSM and immediate reconstruction was performed. Age younger than 50 years, tumor size > 40 mm, high tumor grade, tumor necrosis, surgical margins < 1 mm, type of biopsy (excisional versus core), and SSM type were examined as risk factors for recurrence., Results: Mean followup was 82.3 months (range 4.9 to 123.2 months). Recurrences developed in 11 patients (5.1%), including: local (n = 7; 3.3%), regional (n = 2; 0.9%), and distant (n = 2; 0.9%). All seven local recurrences were detected by physical examination. No patients received adjuvant radiation therapy. Two of 19 patients with surgical margins < 1 mm developed LR (10.5%). Univariate analysis showed high tumor grade (p = .019) to influence LR., Conclusions: The incidence of local recurrence of DCIS after SSM is similar to conventional total mastectomy. Reexcision of close margins should be performed if possible and adjuvant radiation therapy should be considered. more...
- Published
- 2007
- Full Text
- View/download PDF
38. Relative stiffness of beta titanium archwires.
- Author
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Johnson E
- Subjects
- Elasticity, Humans, Materials Testing, Molybdenum chemistry, Niobium chemistry, Orthodontic Appliance Design, Stainless Steel chemistry, Stress, Mechanical, Surface Properties, Torque, Dental Alloys chemistry, Orthodontic Wires, Titanium chemistry
- Abstract
The number of vendors of beta titanium (TMA type) wires has recently expanded dramatically. Samples of all the available sizes were obtained from most of the major beta titanium vendors. Three new square sizes are now also available. A total of 34 wire samples were tested for stiffness using the new ADA three-point wire-testing jig. Results show that not all beta titanium wires have the same stiffness. The range of variation was from small to large depending on the nominal wire size. There was also a spread of 1.67% to 4.27% in the standard deviation of the average stiffness from vendor to vendor. Burstone's Vari-modulus of elasticity is discussed along with how the properties of beta titanium could be integrated with his concepts. Strategies for using the new sizes of rectangular beta titanium wires for torque are discussed, including their use as working wires and finishing wires. The possibility of replacing stainless steel wires in the final finishing stages is also discussed. more...
- Published
- 2003
- Full Text
- View/download PDF
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