Josephine Marriage

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 75dBSPL. 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 3 dB 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. Sumario Evaluamos si existen diferencias en los requerimientos de ganancia entre usuarios inexpertos o experimentados, al adaptarles auxiliares auditivos (AA) de compresión multibanda. Se usaron tres procedimientos para adaptación inicial: los métodos Cambridge para ecualización (CAMEQ) y restauración (CAMREST) de la intensidad subjetiva y el de ingreso/egreso para nivel de sensación deseada (DSL[i/o] ). Se adaptaron AA digitales Danalogic 163D a veinte usuarios experimentados y a 20 nuevos, con pérdidas neurosensoriales medias a severas, usando balanceadamente los tres procedimientos. Los nuevos usuarios fueron pre-adaptados con ganancias ligeramente reducidas, antes de la adaptación “formal”. Inmediatamente después de ésta y una semana después, con cada uno de los procedimientos de adaptación, se ajustaron las ganancias con el mínimo necesario para lograr adaptaciones aceptables. El monto del ajuste fue la principal medición para basar la adaptación inicial. En promedio, los nuevos usuarios requirieron disminución de la ganancia con todos los métodos, siendo mayor con DSL[i/o] que con CAMEQ o CAMREST. Para los experimentados, los ajustes de ganancia fueron menores con CAMEQ y CAMREST, pero más amplios y en su mayoría negativos para DSL[i/o]. Después de estos ajustes de ganancia los AA fueron usados no menos de 3 semanas, antes de llenar el Perfil Abreviado de Beneficio de AA APHAB) y de tomar parte en mediciones de laboratorio del umbral de recepción del lenguaje (SRT) con palabras, sin y con ruido de fondo fijo o fluctuante, en niveles de 60 y 75 dB SPL. Las puntuaciones del APHAB y del SRT no variaron significativamente con los tres métodos. Concluimos que el CAMEQ y el CAMREST permiten una adaptación inicial más apropiada que el DSL[i/o]. En usuarios inexpertos, fue típicamente necesario reducir la ganancia en cerca de 3 dB cuando la prescripción se hizo con CAMEQ o CAMREST, aunque el monto de la reducción puede depender de la pérdida auditiva. Un análisis de los ajustes de ganancia como función del orden de las pruebas, mostró evidencias de mayor tolerancia a la amplificación en frecuencias agudas conforme aumentó la experiencia en los cuatro meses del protocolo, pero este efecto no varió entre usuarios experimentados o inexpertos.

Comparison of three procedures for initial fitting of compression hearing aids. I. Experienced users, fitted bilaterally

Abstract We compared the effectiveness of three procedures for the initial fitting of hearing aids with multiband compression: (1) CAMEQ, which aims to amplify speech so as to give equal loudness per critical band over the frequency range important for speech intelligibility, and to give similar overall loudness to ‘normal’; (2) CAMREST, which aims to amplify speech so as to restore ‘normal’ specific loudness patterns, over a wide range of speech levels; (3) DSL I/O, which aims to map the dynamic range of normally hearing people into the reduced dynamic range of hearing-impaired people, with ‘full’ restoration of audibility. Ten experienced hearing aid users with moderate sensorineural loss were fitted bilaterally with Danalogic 163D digital hearing aids, using each procedure in turn; the order was counterbalanced across subjects. The fitting required specification of gains for input levels of 55 and 80 dB SPL at six centre frequencies. Real-ear measurements were made to ensure that target gains were reached (±3 dB). Immediately after fitting with a given procedure, and one week after fitting, the gains were adjusted when required by the minimum amount necessary to achieve acceptable fittings. The amount of adjustment required provides one measure of the adequacy of the initial fitting. On average, the adjustments were smallest for the CAMEQ procedure. The gain changes were slightly larger for the CAMREST procedure and were largest of all for DSL I/O. For the latter, the gain changes were mostly negative, especially for high frequencies and the higher input level. This indicates that the DSL I/O procedure prescribes more high-frequency gain than is preferred by adult users. After these gain adjustments, users wore the aids for at least three weeks before filling out the 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 dB SPL. Following these tests, the hearing aids were re-fitted with the next procedure. 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.

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. 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 normalhearing people into the reduced dynamic range of hearingimpaired 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. Sumario Este trabajo es el segundo de una serie en la que se comparan tres procedimientos para la adaptacio´n inicial de auxiliares auditivos (HA) multicanal con compresio´n. El primer reporto´ los resultados de un grupo de 10 usuarios experimentados con HA en ambos oi´dos. Este reporta los resultados de un grupo diferente, de 10 usuarios experimentados con adaptacio´n unilateral de HA. Los tres procedimientos fueron: (1) CAMEQ, que pretende amplificar el lenguaje de modo que proporcione una intensidad subjetiva igual por bandas criticas, en el rango de frecuencias de 500-5000 Hz, y que proporcione tambie´n una intensidad subjetiva globalmente similar en la zona de normalidad y en un amplio rango de niveles de lenguaje; (2) CAMREST, que tiende a amplificar el lenguaje de modo que se restauren patrones especi´ficos normales de intensidad subjetiva en un amplio rango de niveles de lenguaje; (3) DSL [i/o] que pretende mapear el rango dina´mico de personas normo-oyentes en el rango dina´mico reducido de personas hipoacu´sicas, con restauracio´n completa de la audibilidad. A cada sujeto se le adapto´ un HA digital Danalogic 163D usando los tres procedimientos de adaptacio´n; el orden de presentacio´n en todos los sujetos se mantuvo balanceado. Se verificaron las ganancias de insercio´n con niveles de ingreso de 55 y 80 dB SPL usando mediciones de oidoreal. Inmediatamente despue´s de la adaptacio´n con un determinado procedimiento y una semana despue´s, se ajustaron las ganancias, cuando fue necesario, con el mi´nimo necesario para una adaptacio´n aceptable. En promedio, los ajustes fueron mas pequen˜os con el CAMREST, ligeramente mayores con CAMEQ y los mayores de todos, con DSL [i/o]. Con DSL [i/o], los cambios de ganancia fueron en su mayori´a negativos, especialmente para las frecuencias agudas y los niveles de ingreso mayores. Despue´s de los ajustes de ganancia, los sujetos usaron sus auxiliares por al menos 3 semanas antes de medir los umbrales de recepcio´n de lenguaje (SRTs) con oraciones sin ruido y con ruido de fondo estacionario o fluctuante. Tambie´n se aplico´ el cuestionario APHAB. Los HA fueron entonces readaptados con el procedimiento que segui´a. Las puntuaciones de SRTs y APHAB no difirieron significativamente entre los tres procedimientos. Concluimos que CAMEQ y CAMREST permiten una adaptacio´n inicial ma´s apropiada que el DSL [i/o] en usuarios experimentados de HA en un solo oi´do. La comparacio´n con nuestros resultados anteriores basados en las adaptaciones bilaterales, sugieren que las ganancias preferidas son similares en las adaptaciones unilaterales y bilaterales.

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.

The reliability of the SCAN test: results from a primary school population in the UK

Abstract The SCAN test utilizes a pre-recorded tape, with carrier phrase and target words spoken by an American English speaker, to screen for central auditory processing disorders in children. The aim of the present study was to establish whether the normative data, derived from American school children, are applicable to a UK primary school population. The SCAN test was administered to 133 British primary school children with normal hearing, stratified into one-year age bands. Mean scores from the UK sample were found to be significantly lower than US mean scores for the most of the age bands. Analysis of word errors indicates accent and word familiarity effects. This evaluation of the SCAN indicates that the test is not directly applicable to British children as currently normalized. The present study provides interim norms for the American recording for age bands six to 11 years. It is recommended that the test material is recorded by a UK English speaker, with substitution of high error-rate target words, followed by normative data collection for the new test material.

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 hearingimpaired 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 childs 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 lest results showed greater variability. Although mean scores were higher for WDRC than for linear processing, the effects were of marginal statistical significance.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 childs 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.

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.

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.

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.