Interactions of Hearing Aid Compression Release Time and Fitting Formula: Effects on Speech Acoustics

2003 ◽  
Vol 14 (02) ◽  
pp. 059-071 ◽  
Author(s):  
John C. Ellison ◽  
Frances P. Harris ◽  
Thomas Muller

The effects of the interaction of compression release time and prescribed gain on running speech processed through a hearing aid on KEMAR was investigated. A digital instrument was programmed to fit a mild to moderate sloping hearing loss using probe microphone measures to reach targets prescribed by NAL-NL1, DSL I/O, FIG.6 or ASA2p with release times of 40 and 640 ms for each condition. Recordings were made through KEMAR and analyzed to determine the long-term-average-speech spectra, consonant-to-vowel ratios and the RMS amplitude of 32 phonemic units. Aided and unaided results were compared. Within each prescriptive formula, changes in release time affected all of the speech measures subsequent to programming the instrument to a static-composite signal. The short release-time condition produced the greatest alteration to the speech signal. Release time may need consideration when fitting hearing aids to target gain prescriptions.

Author(s):  
Marc Brennan ◽  
Ryan Mccreery ◽  
John Massey

Background: Adults and children with sensorineural hearing loss (SNHL) have trouble understanding speech in rooms with reverberation when using hearing aid amplification. While the use of amplitude compression signal processing in hearing aids may contribute to this difficulty, there is conflicting evidence on the effects of amplitude compression settings on speech recognition. Less clear is the effect of a fast release time for adults and children with SNHL when using compression ratios derived from a prescriptive procedure. Purpose: To determine whether release time impacts speech recognition in reverberation for children and adults with SNHL and to determine if these effects of release time and reverberation can be predicted using indices of audibility or temporal and spectral distortion. Research Design: A quasi-experimental cohort study. Participants used a hearing aid simulator set to the Desired Sensation Level algorithm m[i/o] for three different amplitude compression release times. Reverberation was simulated using three different reverberation times. Participants: Participants were 20 children and 16 adults with SNHL. Data Collection and Analyses: Participants were seated in a sound-attenuating booth and then nonsense syllable recognition was measured. Predictions of speech recognition were made using indices of audibility, temporal distortion, and spectral distortion and the effects of release time and reverberation were analyzed using linear mixed models. Results: While nonsense syllable recognition decreased in reverberation; release time did not significantly affect nonsense syllable recognition. Participants with lower audibility were more susceptible to the negative effect of reverberation on nonsense syllable recognition. Conclusions: We have extended previous work on the effects of reverberation on aided speech recognition to children with SNHL. Variations in release time did not impact the understanding of speech. An index of audibility best predicted nonsense syllable recognition in reverberation and, clinically, these results suggest that patients with less audibility are more susceptible to nonsense syllable recognition in reverberation.


2019 ◽  
Vol 28 (4) ◽  
pp. 877-894
Author(s):  
Nur Azyani Amri ◽  
Tian Kar Quar ◽  
Foong Yen Chong

Purpose This study examined the current pediatric amplification practice with an emphasis on hearing aid verification using probe microphone measurement (PMM), among audiologists in Klang Valley, Malaysia. Frequency of practice, access to PMM system, practiced protocols, barriers, and perception toward the benefits of PMM were identified through a survey. Method A questionnaire was distributed to and filled in by the audiologists who provided pediatric amplification service in Klang Valley, Malaysia. One hundred eight ( N = 108) audiologists, composed of 90.3% women and 9.7% men (age range: 23–48 years), participated in the survey. Results PMM was not a clinical routine practiced by a majority of the audiologists, despite its recognition as the best clinical practice that should be incorporated into protocols for fitting hearing aids in children. Variations in practice existed warranting further steps to improve the current practice for children with hearing impairment. The lack of access to PMM equipment was 1 major barrier for the audiologists to practice real-ear verification. Practitioners' characteristics such as time constraints, low confidence, and knowledge levels were also identified as barriers that impede the uptake of the evidence-based practice. Conclusions The implementation of PMM in clinical practice remains a challenge to the audiology profession. A knowledge-transfer approach that takes into consideration the barriers and involves effective collaboration or engagement between the knowledge providers and potential stakeholders is required to promote the clinical application of evidence-based best practice.


2002 ◽  
Vol 13 (09) ◽  
pp. 503-520
Author(s):  
Francis Kuk ◽  
Andre Marcoux

Ensuring consistent audibility is an important objective when fitting hearing aids to children. This article reviews the factors that could affect the audibility of the speech signals to children. These factors range from a precise determination of the child's hearing loss to an accurate specification of gain in the chosen hearing aids. In addition, hearing aid technology and features such as multichannel processing, directional microphones, and feedback cancellation that could affect the achievement of consistent audibility are reviewed.


1980 ◽  
Vol 89 (5_suppl) ◽  
pp. 79-83
Author(s):  
Richard Lippmann

Following the Harvard master hearing aid study in 1947 there was little research on linear amplification. Recently, however, there have been a number of studies designed to determine the relationship between the frequency-gain characteristic of a hearing aid and speech intelligibility for persons with sensorineural hearing loss. These studies have demonstrated that a frequency-gain characteristic that rises at a rate of 6 dB/octave, as suggested by the Harvard study, is not optimal. They have also demonstrated that high-frequency emphasis of 10–40 dB above 500–1000 Hz is beneficial. Most importantly, they have demonstrated that hearing aids as they are presently being fit do not provide maximum speech intelligibility. Percent word correct scores obtained with the best frequency-gain characteristics tested in various studies have been found to be 9 to 19 percentage points higher than scores obtained with commercial aids owned by subjects. This increase in scores is equivalent to an increase in signal-to-noise ratio of 10 to 20 dB. This is a significant increase which could allow impaired listeners to communicate in many situations where they presently cannot. These results demonstrate the need for further research on linear amplification aimed at developing practical suggestions for fitting hearing aids.


2018 ◽  
Vol 29 (08) ◽  
pp. 706-721 ◽  
Author(s):  
Michael Valente ◽  
Kristi Oeding ◽  
Alison Brockmeyer ◽  
Steven Smith ◽  
Dorina Kallogjeri

AbstractThe American Speech-Language-Hearing Association (ASHA) and American Academy of Audiology (AAA) have created Best Practice Guidelines for fitting hearing aids to adult patients. These guidelines recommend using real-ear measures (REM) to verify that measured output/gain of hearing aid(s) match a validated prescriptive target. Unfortunately, approximately 70–80% of audiologists do not routinely use REM when fitting hearing aids, instead relying on a manufacturer default “first-fit” setting. This is problematic because numerous studies report significant differences in REM between manufacturer first-fit and the same hearing aids using a REM or programmed-fit. These studies reported decreased prescribed gain/output in the higher frequencies for the first-fit compared with the programmed fit, which are important for recognizing speech. Currently, there is little research in peer-reviewed journals reporting if differences between hearing aids fitted using a manufacturer first-fit versus a programmed-fit result in significant differences in speech recognition in quiet, noise, and subjective outcomes.To examine if significant differences were present in monosyllabic word and phoneme recognition (consonant-nucleus-consonant; CNC) in quiet, sentence recognition in noise (Hearing in Noise Test; HINT), and subjective outcomes using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Speech, Spatial and Qualities of Hearing (SSQ) questionnaires between hearing aids fit using one manufacturer’s first-fit and the same hearing aids with a programmed-fit using REM to National Acoustic Laboratories Nonlinear Version 2 (NAL-NL2) prescriptive target.A double-blind randomized crossover design was used. Throughout the study, one investigator performed all REM whereas a second investigator measured speech recognition in quiet, noise, and scored subjective outcome measures.Twenty-four adults with bilateral normal sloping to moderately severe sensorineural hearing loss with no prior experience with amplification.The hearing aids were fit using the proprietary manufacturer default first-fit and a programmed-fit to NAL-NL2 using real-ear insertion gain measures. The order of the two fittings was randomly assigned and counterbalanced. Participants acclimatized to each setting for four weeks and returned for assessment of performance via the revised CNC word lists, HINT, APHAB, and SSQ for the respective fitting.(1) A significant median advantage of 15% (p < 0.001; 95% CI: 9.7–24.3%) for words and 7.7% (p < 0.001; 95% CI: 5.9–10.9%) for phonemes for the programmed-fit compared with first-fit at 50 dB sound pressure level (SPL) and 4% (p < 0.01; 95% CI: 1.7–6.3%) for words at 65 dB SPL; (2) No significant differences for the HINT reception threshold for sentences (RTS); (3) A significant median advantage of 4.2% [p < 0.04; 95% confidence interval (CI): −0.6–13.2%] for the programmed-fit compared with the first-fit for the background noise subscale problem score for the APHAB; (4) No significant differences on the SSQ.Improved word and phoneme recognition for soft and words for average speech in quiet were reported for the programmed-fit. Seventy-nine percent of the participants preferred the programmed-fitting versus first-fit. Hearing aids, therefore, should be verified and programmed using REM to a prescriptive target versus no verification using a first-fit.


2017 ◽  
Vol 28 (02) ◽  
pp. 109-118 ◽  
Author(s):  
Elizabeth Convery ◽  
Gitte Keidser ◽  
Mark Seeto ◽  
Margot McLelland

Background: Hearing aids and personal sound amplification products that are designed to be self-fitted by the user at home are becoming increasingly available in the online marketplace. While these devices are often marketed as a low-cost alternative to traditional hearing health-care, little is known about people’s ability to successfully use and manage them. Previous research into the individual components of a simulated self-fitting procedure has been undertaken, but no study has evaluated performance of the procedure as a whole using a commercial product. Purpose: To evaluate the ability of a group of adults with a hearing loss to set up a pair of commercially available self-fitting hearing aids for their own use and to investigate factors associated with a successful outcome. Research Design: An interventional study that used regression analysis to identify potential contributors to the outcome. Study Sample: Forty adults with mild to moderately severe hearing loss participated in the study: 20 current hearing aid users (the “experienced” group) and 20 with no previous amplification experience (the “new” group). Twenty-four participants attended with partners, who were present to offer assistance with the study task as needed. Data Collection and Analysis: Participants followed a set of written, illustrated instructions to perform a multistep self-fitting procedure with a commercially available self-fitting hearing aid, with optional assistance from a lay partner. Standardized measures of cognitive function, health literacy, locus of control, hearing aid self-efficacy, and manual dexterity were collected. Statistical analysis was performed to examine the proportion of participants in each group who successfully performed the self-fitting procedure, factors that predicted successful completion of the task, and the contributions of partners to the outcome. Results: Fifty-five percent of participants were able to successfully perform the self-fitting procedure. Although the same success rate was observed for both experienced and new participants, the majority of the errors relating to the hearing test and the fine-tuning tasks were made by the experienced participants, while all of the errors associated with physically customizing the hearing aids and most of the insertion errors were made by the new participants. Although the majority of partners assisted in the self-fitting task, their contributions did not significantly influence the outcome. Further, no characteristic or combination of characteristics reliably predicted which participants would be successful at the self-fitting task. Conclusions: Although the majority of participants were able to complete the self-fitting task without error, the provision of knowledgeable support by trained personnel, rather than a fellow layperson, would most certainly increase the proportion of users who are able to achieve success. Refinements to the instructions and the physical design of the hearing aid may also serve to improve the success rate. Further evaluation of the range of self-fitting hearing aids that are now on the market should be undertaken.


2016 ◽  
Vol 27 (08) ◽  
pp. 619-627 ◽  
Author(s):  
Jourdan T. Holder ◽  
Erin M. Picou ◽  
Jill M. Gruenwald ◽  
Todd A. Ricketts

Background: The American National Standards Institute (ANSI) provides standards used to govern standardization of all hearing aids. If hearing aids do not meet specifications, there are potential negative implications for hearing aid users, professionals, and the industry. Recent literature has not investigated the proportion of new hearing aids in compliance with the ANSI specifications for quality control standards when they arrive in the clinic before dispensing. Purpose: The aims of this study were to determine the percentage of new hearing aids compliant with the relevant ANSI standard and to report trends in electroacoustic analysis data. Research Design: New hearing aids were evaluated for quality control via the ANSI S3.22-2009 standard. In addition, quality control of directional processing was also assessed. Study Sample: Seventy-three behind-the-ear hearing aids from four major manufacturers, that were purchased for clinical patients were evaluated before dispensing. Data Collection and Analysis: Audioscan Verifit (version 3.1) hearing instrument fitting system was used to complete electroacoustic analysis and directional processing evaluation of the hearing aids. Frye’s Fonix 8000 test box system (Fonix 8000) was also used to cross-check equivalent input noise (EIN) measurements. These measurements were then analyzed for trends across brands and specifications. Results: All of the hearing aids evaluated were found to be out of specification for at least one measure. EIN and attack and release times were the measures most frequently out of specification. EIN was found to be affected by test box isolation for two of the four brands tested. Systematic discrepancies accounted for ˜93% of the noncompliance issues, while unsystematic quality control issues accounted for the remaining 7%. Conclusions: The high number of systematic discrepancies between the data collected and the specifications published by the manufacturers suggests there are clear issues related to the specific protocols used for quality control testing. These issues present a significant barrier for hearing aid dispensers when attempting to accurately determine if a hearing aid is functioning appropriately. The significant number of unsystematic discrepancies supports the continued importance of quality control measures of new and repaired hearing aids to ensure that the device is functioning properly before it is dispensed and to avoid future negative implications of fitting a faulty device.


2008 ◽  
Vol 123 (2) ◽  
pp. 170-176 ◽  
Author(s):  
K Badran ◽  
A K Arya ◽  
D Bunstone ◽  
N Mackinnon

AbstractObjectives:To report cases of long-term surgical complications, implant failure and revision surgery, within a large bone-anchored hearing aid programme.Study design:Retrospective, case–cohort study.Setting:Tertiary referral centre.Patients:One hundred and sixty-five adults and children who had undergone a total of 177 bone-anchored hearing aid implantations.Intervention:Diagnosis and explanation of adverse events and device failure.Main outcome measures:Operative complications and survival analysis, surgical challenges related to revisions, and causes of failure.Results:Twenty-one per cent of patients (3.4 per cent of those observed) suffered from skin reactions; this rate did not increase over time. Seventeen per cent had loss of osseointegration at a median interval of 6.3 months. Loss of osseointegration was observed more frequently in patients with a 3 mm compared with a 4 mm fixture (p < 0.001). Intra-operatively, the only complication was bleeding, occurring in 3 per cent of patients. Post-operative complications included: primary bleeding (2 per cent); severe skin reactions requiring intravenous antibiotics, cautery or grafting (8 per cent); thickening or overgrowth of skin requiring excision (8 per cent); failure of osseointegration requiring a new fixture (18 per cent); and graft necrosis requiring revision (1 per cent). In two patients, it was necessary to explore the area to remove overgrowth of bone. In 16 patients (10 per cent), the bone-anchored hearing aid had to be abandoned due to failure of osseointegration (n = 4), dissatisfaction with the aid (n = 6), intolerable pain (n = 4), hair growth around the abutment (n = 1) or recurrent infections (n = 1). In 12 of these patients, the bone-anchored hearing aid was removed surgically. Overall, 57 patients (34 per cent) underwent revision surgery.Conclusion:Awareness of complications is becoming increasingly important in bone-anchored hearing aid programme. A substantial workload of device maintenance should be anticipated, and patients should be appropriately counselled beforehand. Ninety per cent of our patients chose to persevere with this form of hearing rehabilitation.


2004 ◽  
Vol 15 (09) ◽  
pp. 605-615 ◽  
Author(s):  
Thomas F. Muller ◽  
Frances P. Harris ◽  
John C. Ellison

Eighteen experienced hearing aid users with mild to moderate sensorineural hearing loss were fit with a digital hearing instrument. An adaptive procedure was used to determine their preferred gain setting for continuous speech under six conditions. Release time (RT) was set to 40, 160, or 640 msec. A prerecorded speech stimulus was presented in quiet or in the presence of multitalker babble (10 dB signal-to-babble ratio); all other compression variables were fixed. Real-ear data obtained with settings for each condition suggest that RT did not affect gain preference; however, subjects preferred higher gain in the presence of the multitalker babble. The RMS amplitudes of 30 phonemic units were calculated using ear canal recordings of the speech stimulus for each subject in each condition. Altering RT resulted primarily in decreased amplitude with increased RT, but this effect was not predictable across listeners or conditions.


2020 ◽  
Vol 16 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Young Kwon Han ◽  
Kyoungwon Lee

Purpose: Several studies have reported the differences between Korean and other countries’ speech in long-term average speech spectrum (LTASS) and band importance function. Authors tried to identify the conversational speech level, the resulting spectrum, and the LTASS for Korean. The purpose of this study was to support the production of a Korean-type hearing aid fitting formula to effectively improve the sound quality of hearing aids and the communication abilities with hearing aids, and to standardize the sound stimuli required to measure the performance of hearing aids. Methods: A total of 73 participants with normal hearing and with no specific voice and language deficits was voluntarily recruited from capital, Gyeongsang and Jeolla areas. The conversational speech level was measured by vocalizing ‘soft,’ ‘moderate,’ ‘raised,’ and ‘loud’ at a distance of 1.0 m from the speaker. And LTASS was measured by vocalizing it at a distance of 0.2 m from the speaker. Results: There was a difference in the mean of males and females in the conversation level, but no significant regional differences were shown. The conversational speech level corresponding to 30th, 65th, and 99th percentiles was 59.67, 64.74, and 79.07 dB sound pressure level, respectively. And the speech spectrum of 30th, 65th, and 99th percentile and LTASS showed in different forms from the international speech test signal. Conclusion: The results of this study should help to calculate the Korean type hearing aid fitting formula and should be used as the basic data to determine the characteristics of the sound stimuli when measuring the performance of the hearing aid.


Sign in / Sign up

Export Citation Format

Share Document