Development of New Open-Set Speech Material for Use in Clinical Audiology with Speakers of British English.

BACKGROUND: The Chear open-set performance test (COPT), which uses a carrier phrase followed by a monosyllabic test word, is intended for clinical assessment of speech recognition, evaluation of hearing-device performance, and the fine-tuning of hearing devices for speakers of British English. This paper assesses practice effects, test-retest reliability, and the variability across lists of the COPT. METHOD: In experiment 1, 16 normal-hearing participants were tested using an initial version of the COPT, at three speech-to-noise ratios (SNRs). Experiment 2 used revised COPT lists, with items swapped between lists to reduce differences in difficulty across lists. In experiment 3, test-retest repeatability was assessed for stimuli presented in quiet, using 15 participants with sensorineural hearing loss. RESULTS: After administration of a single practice list, no practice effects were evident. The critical difference between scores for two lists was about 2 words (out of 15) or 5 phonemes (out of 50). The mean estimated SNR required for 74% words correct was -0.56 dB, with a standard deviation across lists of 0.16 dB. For the participants with hearing loss tested in quiet, the critical difference between scores for two lists was about 3 words (out of 15) or 6 phonemes (out of 50).

An association between auditory responsiveness of children and duration of entertainment screen time in the early years of life.

OBJECTIVE: To examine whether the responsiveness of young children to simple sounds was associated with entertainment screen time (EST), opportunities for social interaction, and social and communication skills. DESIGN: Parents completed a questionnaire covering, for years one and two, the number of times the child met with other children; the number of words the child spoke; and the daily amount of EST. Social, attention and communication skills were assessed. STUDY SAMPLE: Participants were 118 children, aged 15 to 46 months. They were initially assessed behaviourally using simple sounds. Children who responded to such sounds were denoted the Responsive group. Children who did not were assessed using familiar songs and denoted the Unresponsive group. RESULTS: The two groups did not differ significantly in mean age or the number of opportunities to meet other children. The Unresponsive group had significantly fewer words than the Responsive group at 12 and 24 months and had significantly higher EST than the Responsive group for years 1 and 2. The Unresponsive group showed lower social, attention and communication skills than the Responsive group. CONCLUSIONS: High EST was associated with poorer auditory and social skills. Hence, it may be wise to limit the EST of young children.

Speech discrimination and word identification with a consumer-level bone-conduction headset and remote microphone for children with normal hearing.

OBJECTIVE: This study investigated the use of bone-conduction headsets paired to a wireless, remote microphone on speech discrimination and word identification for children with normal hearing. DESIGN: Children were tested with and without the headset, using the McCormick speech discrimination test in quiet and in speech-shaped noise to measure word-discrimination thresholds. Additionally, open-set word identification in noise was assessed while children were simultaneously engaged in a visual-monitoring task. STUDY SAMPLE: Twenty normal-hearing children, aged 4-11 years. RESULTS: Median word-discrimination threshold in quiet (n = 20) was 20.5 dB(A) without a headset and 11.5 dB(A) with a headset (Z = -3.826, p = 0.0001). In noise, the median word-discrimination threshold (n = 20) was 52 dB(A) without a headset and 40.5 dB(A) with a headset (Z = -3.926, p< 0.0001). For open-set word identification (n = 11), children performed significantly better with a headset than without it, with an average improvement of 23 percentage points (t(10) = -5.227, p = 0.0004, two tailed). CONCLUSIONS: A bone-conduction headset paired to a Bluetooth microphone improved discrimination of distant speech in quiet and in noise and open-set word identification in noise.

Clinicians' views of using cortical auditory evoked potentials (CAEP) in the permanent childhood hearing impairment patient pathway.

Objective: To obtain clinicians' views on the use of cortical auditory evoked potentials (CAEP) in the clinical pathway.Design: A questionnaire aimed at clinicians who use the HEARLab system with the Aided Cortical Assessment (ACA) Module. Results compared for Australians (where HEARLab produced) to other countries.Sample: The questionnaire was completed by 49 clinicians; 33 from Australia and 13 clinicians outside of Australia and 3 clinicians, destination unknown.Results: The findings of this research demonstrated that clinicians using CAEPs found them valuable for clinical practice. CAEPs were used to verify or modify hearing aid fittings and were used for counselling parents to reinforce the need for hearing aids. With the use of speech token as the stimulus clinicians had more relevant information to increase confidence in decision-making on paediatric hearing management.Conclusions: The main benefit from the use of CAEPs (using speech token stimuli) was for infant hearing aid fitting programmes, to facilitate earlier decisions relating to hearing aid fitting, for fine-tuning the aids and as an additional measure for cochlear implant referrals.

Identifying and prioritising unanswered research questions for people with hyperacusis: James Lind Alliance Hyperacusis Priority Setting Partnership.

OBJECTIVE: To determine research priorities in hyperacusis that key stakeholders agree are the most important. DESIGN/SETTING: A priority setting partnership using two international surveys, and a UK prioritisation workshop, adhering to the six-staged methodology outlined by the James Lind Alliance. PARTICIPANTS: People with lived experience of hyperacusis, parents/carers, family and friends, educational professionals and healthcare professionals who support and/or treat adults and children who experience hyperacusis, including but not limited to surgeons, audiologists, psychologists and hearing therapists. METHODS: The priority setting partnership was conducted from August 2017 to July 2018. An international identification survey asked respondents to submit any questions/uncertainties about hyperacusis. Uncertainties were categorised, refined and rephrased into representative indicative questions using thematic analysis techniques. These questions were verified as 'unanswered' through searches of current evidence. A second international survey asked respondents to vote for their top 10 priority questions. A shortlist of questions that represented votes from all stakeholder groups was prioritised into a top 10 at the final prioritisation workshop (UK). RESULTS: In the identification survey, 312 respondents submitted 2730 uncertainties. Of those uncertainties, 593 were removed as out of scope, and the remaining were refined into 85 indicative questions. None of the indicative questions had already been answered in research. The second survey collected votes from 327 respondents, which resulted in a shortlist of 28 representative questions for the final workshop. Consensus was reached on the top 10 priorities for future research, including identifying causes and underlying mechanisms, effective management and training for healthcare professionals. CONCLUSIONS: These priorities were identified and shaped by people with lived experience, parents/carers and healthcare professionals, and as such are an essential resource for directing future research in hyperacusis. Researchers and funders should focus on addressing these priorities.

Using a Bone-Conduction Headset to Improve Speech Discrimination in Children With Otitis Media With Effusion.

The recommended management for children with otitis media with effusion (OME) is 'watchful waiting' before considering grommet surgery. During this time speech and language, listening skills, quality of life, social skills, and outcomes of education can be jeopardized. Air-conduction (AC) hearing aids are problematic due to fluctuating AC hearing loss. Bone-conduction (BC) hearing is stable, but BC hearing aids can be uncomfortable. Both types of hearing aids are costly. Given the high prevalence of OME and the transitory nature of the accompanying hearing loss, cost-effective solutions are needed. The leisure industry has developed relatively inexpensive, comfortable, high-quality BC headsets for transmission of speech or music. This study assessed whether these headsets, paired with a remote microphone, improve speech discrimination for children with OME. Nineteen children aged 3 to 6 years receiving recommended management in the United Kingdom for children with OME participated. Word-discrimination thresholds were measured in a sound-treated room in quiet and with 65 dB(A) speech-shaped noise, with and without a headset. The median threshold in quiet (N = 17) was 39 dB(A) (range: 23-59) without a headset and 23 dB(A) (range: 9-35) with a headset (Z = -3.519, p < .001). The median threshold in noise (N = 19) was 59 dB(A) (range: 50-63) without a headset and 45 dB(A) (range: 32-50) with a headset (Z = -3.825, p < .001). Thus, the use of a BC headset paired with a remote microphone significantly improved speech discrimination in quiet and in noise for children with OME.

A qualitative review of parents' perspectives on the value of CAEP recording in influencing their acceptance of hearing devices for their child.

Objective: To obtain a parental perspective on how audiological tests, including recording cortical auditory-evoked potentials (CAEP) to speech sounds, influenced their uptake of hearing devices for their infant. Design: A focus group was established by parents of hearing-impaired children. A facilitator explored how audiology tests influenced their understanding and management of hearing loss in their child and their acceptance of hearing aids or cochlear implant referral. The views were transcribed and thematic analysis was used to understand key topics. Study samples: Eight sets of parents participated. Their children had been enrolled in an audiology pathway that included CAEP testing. The sample included six children who were aided, one child who was going through the implant assessment and one child who was implanted. Results: Parents reported that it was important for them to understand the test results because this influenced acceptance of hearing aids and cochlear implant assessments. Seven sets of parents had not understood ABR results, while six reported that CAEPs had helped them to understand their child's hearing and need for intervention. Conclusion: Compliance with early hearing aid use and referral for cochlear implant depends upon parents' understanding of their infant's hearing loss by including CAEPs in the audiology pathway.

Closed-Set Speech Discrimination Tests for Assessing Young Children.

OBJECTIVE: The main objective of this study is to obtain data assessing normative scores, test-retest reliability, critical differences, and the effect of age for two closed-set consonant-discrimination tests. DESIGN: The two tests are intended for use with children aged 2 to 8 years. The tests were evaluated using normal-hearing children within the appropriate age range. The tests were (1) the closed-set consonant confusion test (CCT) and (2) the consonant-discrimination subtest of the closed-set Chear Auditory Perception Test (CAPT). Both were word-identification tests using stimuli presented at a low fixed level, chosen to avoid ceiling effects while avoiding the use of background noise. Each test was administered twice. RESULTS: All children in the age range 3 years 2 months to 8 years 11 months gave meaningful scores and were able to respond reliably using a computer mouse or a touch screen to select one of four response options displayed on a screen for each trial. Assessment of test-retest reliability showed strong agreement between the two test runs (interclass correlation ≥ 0.8 for both tests). The critical differences were similar to those for other monosyllabic speech tests. Tables of these differences for the CCT and CAPT are provided for clinical use of the measures. Performance tended to improve with increasing age, especially for the CCT. Regression equations relating mean performance to age are given. CONCLUSIONS: The CCT is appropriate for children with developmental age in the range 2 to 4.5 years and the CAPT is appropriate as a follow-on test from the CCT. If a child scores 80% or more on the CCT, they can be further tested using the CAPT, which contains more advanced vocabulary and more difficult contrasts. This allows the assessment of consonant perception ability and of changes over time or after an intervention.

Comparison of Different Hearing Aid Prescriptions for Children.

OBJECTIVES: To assess whether there are significant differences between speech scores for different hearing aid prescription methods, specifically DSL i/o, DSL V, and NAL-NL1, using age-appropriate closed- and open-set speech tests with young children, designed to avoid floor and ceiling effects. DESIGN: Participants were 44 children with moderate or severe bilateral hearing loss, 8 aged 2 to 3 years, 15 aged 4 to 5 years, and 21 aged 6 to 9 years. Children wore bilateral hearing aids fitted with each prescription method in turn in a balanced double-blind design. The speech tests used with each child (and for some tests the levels) were chosen so as to avoid floor and ceiling effects. For the closed-set tests, the level used was selected for each child based on their hearing loss. The tests used were: (1) The closed-set Consonant Confusion Test of word identification; (2) The closed-set Chear Auditory Perception Test (CAPT) of word identification. This has separate sections assessing discrimination of consonants and vowels and detection of consonants; (3) The open-set Cambridge Auditory Word Lists for testing word identification at levels of 50 and 65 dBA, utilizing 10 consonant-vowel-consonant real words that are likely to be familiar to children aged 3 years or older; (4) The open-set Common Phrases Test to measure the speech reception threshold in quiet; (5) Measurement of the levels required for identification of the Ling 5 sounds, using a recording of the sounds made at the University of Western Ontario. RESULTS: Scores for the Consonant Confusion Test and CAPT consonant discrimination and consonant detection were lower for the NAL-NL1 prescription than for the DSL prescriptions. Scores for the CAPT vowel-in-noise discrimination test were higher for DSL V than for either of the other prescriptions. Scores for the Cambridge Auditory Word Lists did not differ across prescriptions for the level of 65 dBA, but were lower for the NAL-NL1 prescription than for either of the DSL prescriptions for the level of 50 dBA. The speech reception threshold measured using the Common Phrases Test and the levels required for identification of the Ling 5 sounds were higher (worse) for the NAL-NL1 prescription than for the DSL prescriptions. CONCLUSIONS: The higher gains prescribed by the DSL i/o and DSL V prescription methods relative to NAL-NL1 led to significantly better detection and discrimination of low-level speech sounds.

Role of Cortical Auditory Evoked Potentials in Reducing the Age at Hearing Aid Fitting in Children With Hearing Loss Identified by Newborn Hearing Screening.

Recording of free-field cortical auditory evoked potential (CAEP) responses to speech tokens was introduced into the audiology management for infants with a permanent childhood hearing impairment (PCHI) during 2011-2015 at a U.K. service. Children with bilateral PCHI were studied from two sequential cohorts. Thirty-four children had followed an audiology pathway prior to CAEP introduction, and 44 children followed a pathway after the introduction of CAEP and were tested with unaided and aided CAEP responses. Data analysis explored the age of diagnosis, hearing aid fitting, and referral for cochlear implant (CI) assessment for each of these groups. CAEP offered a novel educative process for the parents and audiologists supporting decision-making for hearing aid fitting and CI referral. Delays in hearing aid fitting and CI referral were categorized as being due to the audiologist's recommendation or parental choice. Results showed that the median age of hearing aid fitting prior to CAEP introduction was 9.2 months. After the inclusion of CAEP recording in the infant pathways, it was 3.9 months. This reduction was attributable to earlier fitting of hearing aids for children with mild and moderate hearing losses, for which the median age fell from 19 to 5 months. Children with profound hearing loss were referred for CI assessment at a significantly earlier age following the introduction of CAEP. Although there has also been a national trend for earlier hearing aid fitting in children, the current study demonstrates that the inclusion of CAEP recording in the pathway facilitated earlier hearing aid fitting for milder impairments.

Evaluating recommended audiometric changes to candidacy using the speech intelligibility index.

INTRODUCTION: The National Institute of Health and Care Excellence (NICE) has derived candidacy guidelines for cochlear implants in the UK based on audiometric thresholds (90 dB HL or above at 2 and 4 kHz; hereafter referred to as the 90 dB HL criteria). Recent research has proposed that these criteria should be changed to 80 dB HL at 2 and 4 kHz (hereafter referred to as the 80 dB HL criteria) in the ear to be implanted. METHODS: In this study, we analysed aided SII scores derived for different hearing loss profiles falling within the current 90 dB HL criteria and equivalent profiles falling within the new 80 dB HL criteria. RESULTS: The aided SII scores demonstrated that the majority of potential hearing configurations falling within the new proposed 80 dB HL criteria have aided SII values of less than 0.65 (a recommended cut-off point below which there is not sufficient audibility to receive adequate benefit through hearing aids). CONCLUSIONS: This supports the proposed change to the 80 dB HL criterion level and also highlights the additional value of the SII score in supporting candidacy decisions for CI, especially for borderline candidates.

Effects of Modified Hearing Aid Fittings on Loudness and Tone Quality for Different Acoustic Scenes.

OBJECTIVE: To compare loudness and tone-quality ratings for sounds processed via a simulated five-channel compression hearing aid fitted using NAL-NL2 or using a modification of the fitting designed to be appropriate for the type of listening situation: speech in quiet, speech in noise, music, and noise alone. DESIGN: Ratings of loudness and tone quality were obtained for stimuli presented via a loudspeaker in front of the participant. For normal-hearing participants, levels of 50, 65, and 80 dB SPL were used. For hearing-impaired participants, the stimuli were processed via a simulated hearing aid with five-channel fast-acting compression fitted using NAL-NL2 or using a modified fitting. Input levels to the simulated hearing aid were 50, 65, and 80 dB SPL. All participants listened with one ear plugged. For speech in quiet, the modified fitting was based on the CAM2B method. For speech in noise, the modified fitting used slightly (0 to 2 dB) decreased gains at low frequencies. For music, the modified fitting used increased gains (by 5 to 14 dB) at low frequencies. For noise alone, the modified fitting used decreased gains at all frequencies (by a mean of 1 dB at low frequencies increasing to 8 dB at high frequencies). RESULTS: For speech in quiet, ratings of loudness with the NAL-NL2 fitting were slightly lower than the mean ratings for normal-hearing participants for all levels, while ratings with CAM2B were close to normal for the two lower levels, and slightly greater than normal for the highest level. Ratings of tone quality were close to the optimum value ("just right") for both fittings, except that the CAM2B fitting was rated as very slightly boomy for the 80-dB SPL level. For speech in noise, the ratings of loudness were very close to the normal values and the ratings of tone quality were close to the optimal value for both fittings and for all levels. For music, the ratings of loudness were close to the normal values for NAL-NL2 and slightly above normal for the modified fitting. The tone quality was rated as very slightly tinny for NAL-NL2 and very slightly boomy for the modified fitting. For noise alone, the NAL-NL2 fitting was rated as slightly louder than normal for all levels, while the modified fitting was rated as close to normal. Tone quality was rated as slightly sharper for the NAL-NL2 fitting than for the modified fitting. CONCLUSIONS: Loudness and tone quality can sometimes be made slightly closer to "normal" by modifying gains for different listening situations. The modification for music required to achieve "normal" tone quality appears to be less than used in this study.

Using personal response systems to assess speech perception within the classroom: an approach to determine the efficacy of sound field amplification in primary school classrooms.

OBJECTIVES: The assessment of the combined effect of classroom acoustics and sound field amplification (SFA) on children's speech perception within the "live" classroom poses a challenge to researchers. The goals of this study were to determine: (1) Whether personal response system (PRS) hand-held voting cards, together with a closed-set speech perception test (Chear Auditory Perception Test [CAPT]), provide an appropriate method for evaluating speech perception in the classroom; (2) Whether SFA provides better access to the teacher's speech than without SFA for children, taking into account vocabulary age, middle ear dysfunction or ear-canal wax, and home language. DESIGN: Forty-four children from two school-year groups, year 2 (aged 6 years 11 months to 7 years 10 months) and year 3 (aged 7 years 11 months to 8 years 10 months) were tested in two classrooms, using a shortened version of the four-alternative consonant discrimination section of the CAPT. All children used a PRS to register their chosen response, which they selected from four options displayed on the interactive whiteboard. The classrooms were located in a 19th-century school in central London, United Kingdom. Each child sat at their usual position in the room while target speech stimuli were presented either in quiet or in noise. The target speech was presented from the front of the classroom at 65 dBA (calibrated at 1 m) and the presented noise level was 46 dBA measured at the center of the classroom. The older children had an additional noise condition with a noise level of 52 dBA. All conditions were presented twice, once with SFA and once without SFA and the order of testing was randomized. White noise from the teacher's right-hand side of the classroom and International Speech Test Signal from the teacher's left-hand side were used, and the noises were matched at the center point of the classroom (10sec averaging [A-weighted]). Each child's expressive vocabulary age and middle ear status were measured individually and each child's home language and any special educational needs were recorded. RESULTS: All children were able to use the PRS handsets, and the CAPT speech perception test was sufficiently sensitive to highlight differences in perception in the different listening conditions. Scores were higher in quiet than in any noise condition. Results showed that group performance was significantly better with SFA than without it. The main demographic predictor of performance was expressive vocabulary age. SFA gave more benefit to the poorer performers in the group. There were no significant effects on performance relating to middle ear status or home language; however, the size of the population was too small to be able to fully explore these aspects in greater detail. CONCLUSION: PRS together with the CAPT provides a sensitive measure for in situ speech perception testing within the classroom. Vocabulary age has a large effect on a child's ability to perceive the speech signal. SFA leads to improved speech perception, when the speech signal has been degraded because of poor acoustics or background noise and has a particularly large effect for children with lower vocabulary ages.

Evaluation of an aided TEN test for diagnosis of dead regions in the cochlea.

OBJECTIVES: To compare results for the original version of the threshold equalizing noise [TEN(HL)] test for diagnosis of dead regions (DRs) in the cochlea, using stimuli presented via headphones, with results for an aided version of the test, the ATEN test, in which subjects listened to stimuli presented in free field using their own hearing aids. DESIGN: The test tones were warble tones for both the TEN(HL) and the ATEN test. Twenty-five subjects (12 males and 13 females), aged between 12 and 19 yr, with severe or profound sensorineural hearing loss were tested. For each test, two levels of the TEN were used, chosen to fall within the comfortable range of levels for the individual subject. A DR was considered to be present when the TEN(HL) produced at least 10 dB of masking and when the masked threshold was at least 10 dB above the nominal TEN(HL) level. Measurements of the outputs of the hearing aids in response to the TEN(HL) plus the test tones were obtained using a KEMAR acoustic manikin to assess the extent to which distortion or compression might have influenced the outcomes. RESULTS: For the TEN(HL) test, the results were often inconclusive, because the TEN(HL) could not be made sufficiently intense to give at least 10 dB of masking. The incidence of these inconclusive cases was markedly reduced for the ATEN test. There were more positive diagnoses of DRs for the ATEN test than for the TEN(HL) test. The KEMAR measurements indicated that distortion, compression, and/or feedback cancellation probably influenced the outcomes in some cases, leading to a moderate incidence of false positives for the ATEN test, and also some "missed" cases. CONCLUSIONS: The ATEN test leads to a lower incidence of inconclusive results than the TEN(HL) test in the diagnosis of DRs in people with severe to profound hearing loss. However, for some hearing aids the gain changed rapidly as a function of frequency, which undermined the validity of the ATEN test. Also, some hearing aids introduced distortion that probably affected the outcome of the test and gave misleading results. Hence, the ATEN test cannot be recommended for use in the clinic.

Comparison of two adaptive procedures for fitting a multi-channel compression hearing aid.

We compared two adaptive procedures for fitting a multi-channel compression hearing aid. "Camadapt" uses judgements of the loudness of speech stimuli and the tonal quality of music stimuli. "Eartuner" uses judgements of the loudness and clarity of speech stimuli with differing spectral characteristics. Sixteen new users of hearing aids were fitted unilaterally, using each procedure. The fittings were assigned to Programs 1 and 2 in the aid, in a counter-balanced order. Subjects kept a diary of their experiences with each program in everyday life. Following 2-4 weeks of experience, they filled in the APHAB and other questionnaires and were re-fitted using both procedures. Camadapt generally led to higher low-level gains and lower high-level gains than Eartuner. Gains recommended by the procedures did not change following experience. Eight subjects preferred the Camadapt fitting and eight preferred the Eartuner fitting. Most subjects gave high overall satisfaction ratings for both procedures. Test-retest reliability was better for Eartuner than for Camadapt. Preference for the Camadapt fitting was associated with slightly better speech communication with Camadapt, while preference for the Eartuner fitting was associated with fewer problems with aversion for that procedure.

Effects of three amplification strategies on speech perception by children with severe and profound hearing loss.

OBJECTIVE: Traditionally in the United Kingdom, children with severe and profound hearing loss have been fitted with linear, analog hearing aids. Fast-acting, wide-dynamic-range compression (WDRC) has been shown to give better discrimination of speech than linear amplification for moderately hearing-impaired young adults. For severe and profound hearing losses, higher compression ratios are needed. The resultant distortion of the temporal envelope and reduced modulation depth may offset improvements in audibility offered by WDRC. In this study, speech recognition and discrimination were assessed for severely and profoundly hearing-impaired children, using three different amplification strategies, including WDRC. DESIGN: Fifteen children (ages 7 to 15 yr) with severe and profound hearing loss were fitted bilaterally with high-power, multichannel compression hearing aids, incorporating one of three different amplification strategies: linear with peak clipping, linear with compression limiting, or WDRC. Output responses were matched to Desired Sensation Level (DSL i/o) targets. The children wore hearing aids programmed with each of the amplification strategies in turn, for at least 1 wk, in a counterbalanced order across children. After using a particular amplification strategy for at least 1 wk, speech perception tests were carried out. RESULTS: Speech scores on closed-set testing for the profound group showed significant benefit for WDRC over the other two algorithms. None of the other results showed a statistically significant effect of algorithm on speech performance. CONCLUSIONS: WDRC amplification sometimes led to better performance than linear amplification with peak clipping or output limiting, and it never led to poorer performance. Therefore, it appears to be safe to use well-designed WDRC for hearing-impaired children with severe or profound hearing loss.

Comparison of three procedures for initial fitting of compression hearing aids. III. Inexperienced versus experienced users.

We assessed whether gain requirements differ for experienced users and new users when fitted with multi-band compression hearing aids Three procedures for initial fitting were used: the Cambridge method for loudness equalization (CAMEQ), the Cambridge method for loudness restoration (CAMREST), and the desired sensation level input/output (DSL[i/o]) method. Twenty experienced hearing aid users and 20 new users with mild-to-severe sensorineural loss were fitted with Danalogic 163D digital hearing aids, using each procedure in turn in a counter-balanced order. The new users were given a pre-fitting with slightly reduced gains prior to the 'formal' fitting. Immediately after formal fitting with a given procedure, and 1 week after fitting, the gains were adjusted by the minimum amount necessary to achieve acceptable fittings. The amount of adjustment required provided the main measure of the adequacy of the initial fitting. On average, new users required decreases in gain for all procedures, the decreases being larger for DSL[i/o] than for CAMEQ or CAMREST. For experienced users, gain adjustments were small for CAMEQ and CAMREST, but were larger and mostly negative for DSL[i/o]. After these gain adjustments, users wore the aids for at least 3 weeks before filling out the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and taking part in laboratory measurements of the speech reception threshold (SRT) for sentences in quiet and in steady and fluctuating background noise at levels of 60 and 75 dBSPL. The scores on the APHAB test and the SRTs did not differ significantly for the three procedures. We conclude that the CAMEQ and CAMREST procedures provide more appropriate initial fittings than DSL[i/o]. For inexperienced users, gains typically need to be reduced by about 3dB relative to those prescribed by CAMEQ or CAMREST, although the amount of reduction may depend on hearing loss. An analysis of gain adjustments as a function of order of testing provided some evidence for increased tolerance to high-frequency amplification with increasing experience during the 4-month course of the trial, but this effect did not differ for the experienced and new users.

Comparison of three procedures for initial fitting of compression hearing aids. II. Experienced users, fitted unilaterally.

This paper is the second in a series comparing three procedures for the initial fitting of multichannel compression hearing aids. The first paper reported the results for a group of 10 experienced hearing aid users fitted bilaterally. This paper reports the results for a different group of 10 experienced hearing aid users fitted unilaterally. The three procedures were: (1) CAMEQ, which aims to amplify speech so as to give equal loudness per critical band over the frequency range 500-5000 Hz, and to give similar overall loudness to normal over a wide range of speech levels; (2) CAMREST, which aims to amplify speech so as to restore normal specific loudness patterns, over a wide range of speech levels; and (3) DSL [i/o], which aims to map the dynamic range of normal-hearing people into the reduced dynamic range of hearing-impaired people, with full restoration of audibility. Each subject was fitted with one Danalogic 163D digital hearing aid, using each of the three fitting procedures in turn; the order was counter-balanced across subjects. Prescribed insertion gains for 55 and 80 dB SPL input levels were verified using real-ear measurements. Immediately after fitting with a given procedure, and 1 week after fitting. the gains were adjusted, when required, by the minimum amount necessary to achieve acceptable fittings. On average, the adjustments were smallest for the CAMREST procedure, slightly larger for the CAMEQ procedure, and largest of all for DSL [i/o]. For the DSL [i/o] the gain changes were mostly negative, especially for high frequencies and the higher input level. After these gain adjustments, users wore the aids for at least 3 weeks before speech reception thresholds (SRTs) for sentences in quiet and in steady and fluctuating background noise were measured. The APHAB questionnaire was also administered. The hearing aids were then refitted with the next procedure. SRTs and APHAB scores did not differ significantly between the three procedures. We conclude that the CAMEQ and CAMREST procedures provide a more appropriate initial fitting than DSL [i/o] for unilaterally experienced hearing aid wearers. Comparison with our earlier study based on bilateral fittings suggests that the preferred gains are similar for unilateral and bilateral fittings.

New speech tests reveal benefit of wide-dynamic-range, fast-acting compression for consonant discrimination in children with moderate-to-profound hearing loss.

Fast-acting, wide-dynamic-range compression (WDRC) has been shown to give better discrimination of soft speech and shouted speech than linear amplification for moderately hearing-impaired young adults. For severe and profound hearing losses, higher compression ratios are needed. The resultant distortion of the temporal envelope and reduced modulation depth may offset improvements in audibility offered by WDRC. This study compares the effectiveness of WDRC and linear amplification for children with different degrees of hearing loss. Pre-recorded tests of closed-set consonant confusions and open-set word recognition were developed to assess performance. Three groups of subjects (aged 4-14 years) with moderate (51-70 dB), severe (71-90 dB) and profound (91-115 dB) hearing loss were fitted with hearing aids programmed with WDRC or linear amplification. The frequency response was adjusted to match each child's own hearing aid prescription. For each group, stimuli were presented both in quiet and in noise at levels chosen to avoid floor and ceiling effects. Consonant confusion scores for the profound and severe groups combined and for the moderate group were significantly better with WDRC than with linear amplification. Open-set test results showed greater variability. Although mean scores were higher for WDRC than for linear processing, the effects were of marginal statistical significance.