Stuart Gatehouse

The Speech, Spatial and Qualities of Hearing Scale (SSQ)

The Speech, Spatial and Qualities of Hearing Scale (SSQ) is designed to measure a range of hearing disabilities across several domains. Particular attention is given to hearing speech in a variety of competing contexts, and to the directional, distance and movement components of spatial hearing. In addition, the abilities both to segregate sounds and to attend to simultaneous speech streams are assessed, reflecting the reality of hearing in the everyday world. Qualities of hearing experience include ease of listening, and the naturalness, clarity and identifiability of different speakers, different musical pieces and instruments, and different everyday sounds. Application of the SSQ to 153 new clinic clients prior to hearing aid fitting showed that the greatest difficulty was experienced with simultaneous speech streams, ease of listening, listening in groups and in noise, and judging distance and movement. SSQ ratings were compared with an independent measure of handicap. After differences in hearing level were controlled for, it was found that identification, attention and effort problems, as well as spatial hearing problems, feature prominently in the disability-handicap relationship, along with certain features of speech hearing. The results implicate aspects of temporal and spatial dynamics of hearing disability in the experience of handicap. The SSQ shows promise as an instrument for evaluating interventions of various kinds, particularly (but not exclusively) those that implicate binaural function. Sumario La Escala de Audición para el Lenguaje, la Audición Espacial y las Cualidades Auditivas (SSQ) está disen˜ada para medir un rango de discapacidades auditivas en varios ámbitos. Se da atención particular a la captación del lenguaje en una variedad de contexto competitivos, y a los componentes direccionales, de distancia y movimiento de la audición espacial. Además, se evalúan las capacidades para segregar sonidos y de distinguir mensajes lingu¨ísticos simultáneos, que reflejan la realidad de la audición en situaciones cotidianas. La experiencia de las cualidades auditivas incluye la facilidad de escuchar, y la naturalidad, claridad y capacidad de identificar a diferentes hablantes, diferentes piezas musicales e instrumentos, y diferentes sonidos de la vida diaria. La aplicación del SSQ a 153 nuevos clientes, antes de la adaptación de su auxiliar auditivo, mostró que la mayor dificultad era experimentada frente a mensajes lingu¨ísticos simultáneos, en la facilidad para escuchar, la audición en grupos en ruido y ante el juicio sobre la distancia y el movimiento. Las mediciones del SSQ fueron comparadas con una medida independiente de desventaja. Luego de controlar las medidas del nivel auditivo, se encontró que la identificación, la atención y los problemas de esfuerzo, al igual que los problemas de audición espacial, fueron los más relevantes en la relación discapacidad-desventaja. La SSQ se muestra promisoria como instrumento para evaluar intervenciones de varios tipos, particularmente (pero no de manera exclusiva) aquellas que involucran la función auditiva binaural.

Measuring Patient Benefit from Otorhinolaryngological Surgery and Therapy

The Glasgow Benefit Inventory (GBI) is a measure of patient benefit developed especially for otorhinolaryngological (ORL) interventions. Patient benefit is the change in health status resulting from health care intervention. The GBI was developed to be patient-oriented, to be maximally sensitive to ORL interventions, and to provide a common metric to compare benefit across different interventions. The GBI is an 18-item, postintervention questionnaire intended to be given to patients to fill in at home or in the outpatient clinic. In the first part of the paper, five different ORL interventions were retrospectively studied: middle ear surgery to improve hearing, provision of a cochlear implant, middle ear surgery to eradicate ear activity, rhinoplasty, and tonsillectomy. A criterion that was specific to the intervention was selected for each study, so that the patient outcome could be classified as above and below criterion. In all five interventions, the GBI was found to discriminate between above- and below-criterion outcomes. The second part of the paper reports on the results and implications of a factor analysis of patient responses. The factor structure was robust across the study, and so led to the construction of subscales. These subscales yield a profile score that provides information on the different types of patient benefit resulting from ORL interventions. The GBI is sensitive to the different ORL interventions, yet is sufficiently general to enable comparison between each pair of interventions. It provides a profile score, which enables further breakdown of results. As it provides a patient-oriented common metric, it is anticipated that the GBI will assist audit, research, and health policy planning.

The time course and magnitude of perceptual acclimatization to frequency responses: Evidence from monaural fitting of hearing aids

At high presentation levels, normally aided ears yield better performance for speech identification than normally unaided ears, while at low presentation levels the converse is true [S. Gatehouse, J. Acoust. Soc. Am. 86, 2103-2106 (1989)]. To explain this process further, the speech identification abilities of four subjects with bilateral symmetric sensorineural hearing impairment were investigated following provision of a single hearing aid. Results showed significant increases in the benefit from amplifying speech in the aided ear, but not in the control ear. In addition, a headphone simulation of the unaided condition for the fitted ear shows a decrease in speech identification. The benefits from providing a particular frequency spectrum do not emerge immediately, but over a time course of at least 6-12 weeks. The findings support the existence of perceptual acclimatization effects, and call into question short-term methods of hearing aid evaluation and selection by comparative speech identification tests.

Optimal Outcome Measures, Research Priorities, and International Cooperation

&NA; The participants in the Eriksholm Workshop on “Measuring Outcomes in Audiological Rehabilitation Using Hearing Aids” debated three issues that are reported in this article. First, it was agreed that the characteristics of an optimal outcome measure vary as a function of the purpose of the measurement. Potential characteristics of outcome self‐report tools for four common goals of outcome measurement are briefly presented to illustrate this point. Second, 10 important research priorities in outcome measurement were identified and ranked. They are presented with brief discussion of the top five. Third, the concept of generating a brief universally applicable outcome measure was endorsed. This brief data set is intended to supplement existing outcome measures and to promote data combination and comparison across different social, cultural, and health‐care delivery systems. A set of seven core items is proposed for further study.

Effects of bilateral versus unilateral hearing aid fitting on abilities measured by the Speech, Spatial, and Qualities of Hearing scale (SSQ)

The Speech, Spatial and Qualities of Hearing Scale (Gatehouse & Noble, ) was applied to three independent clinical groups: 144 people prior to being fitted with amplification; 118 people with six months experience with unilateral amplification; and 42 people with six months experience with bilateral amplification. For traditional speech hearing contexts (one-on-one, in groups, in quiet, in noise) there was benefit with one aid, and no further benefit with two. By contrast, hearing speech in demanding contexts (divided or rapidly switching attention) showed benefit with one aid and further benefit with two. In the spatial domain, directional hearing showed some benefit with one hearing aid, and particular further benefit in distance and movement discrimination from fitting with two. There was some benefit from unilateral fitting for elements of the qualities domains (clarity, naturalness, recognisability, segregation of sounds), with no consistent sign of further benefit from two. Bilateral fitting added benefit with respect to listening effort. Two hearing aids offer advantage in demanding and dynamic contexts; these contexts are argued as significant in the maintenance of social competence and emotional wellbeing. The present results go toward establishing the real-world advantages of bilateral hearing aid fitting and suggest that previous, inconclusive clinical findings reflect inquiry limited to more traditional areas of hearing function. Sumario Se aplicó la escala de cualidades auditiva, espacial y del lenguaje (Gatehouse & Noble, ) a tres grupos clínicos independientes: 144 personas, antes de adaptarles auxiliares auditivos; 118 personas con 6 meses de experiencia con amplificación unilateral y 42 personas con 6 meses de experiencia con amplificación bilateral. Se encontró beneficio de la amplificación unilateral en el contexto de habla tradicional (uno a uno, en grupo, en silencio y en ruido) y no hubo beneficio posterior en el modo bilateral. En contraste, bajo condiciones de discriminación del lenguaje en contexto demandante (atención dividida o cambio de rápido de atención) hubo beneficio con un solo un auxiliar, y mayor beneficio con dos. En el dominio espacial, hubo cierto beneficio en la audición direccional con un solo auxiliar auditivo y particularmente resultó benéfica la condición bilateral en la discriminación de distancia y movimiento. Hubo cierto beneficio de la condición unilateral para elementos de cualidad (claridad, naturalidad, fácil discriminación, segregación de sonidos) sin signos consistentes de beneficio con amplificación bilateral. La amplificación bilateral benefició el menor esfuerzo para escuchar. Hay ventajas con dos auxiliares auditivos en contexto demandante o dinámico; estos contextos son considerados como significativos en el mantenimiento de la competencia social y el bienestar emocional. Estos resultados se encaminan a establecer las ventajas de la amplificación bilateral en el mundo real y sugieren que los hallazgos clínicos previos e inconclusos, reflejan información limitada a áreas más tradicionales de la función auditiva.

COMPONENTS AND DETERMINANTS OF HEARING AID BENEFIT

This study investigates the measured and perceived disabilities and handicaps and associated auditory performance in 309 first-time hearing aid candidates. The results suggest that both disability and hearing aid benefit may be divided into separate components having particular and separate relationships to predictor variables in terms of both auditory and nonauditory characteristics. This division leads to a better understanding of the problems associated with a hearing impairment and their alleviation (or lack of) by provision of a hearing aid. In addition, the results support the development of more appropriate speech identification measures and suggest a potentidy important role for measures of the temporal properties of the impaired auditory system.

Sound localization in noise in normal-hearing listeners

The ability to localize a click train in the frontal-horizontal plane was measured in quiet and in the presence of a white-noise masker. The experiment tested the effects of signal frequency, signal-to-noise ratio (S/N), and masker location. Clicks were low-pass filtered at 11 kHz in the broadband condition, low-pass filtered at 1.6 kHz in the low-pass condition, and bandpass filtered between 1.6 and 11 kHz in the high-pass condition. The masker was presented at either -90, 0, or +90 deg azimuth. Six signal-to-noise ratios were used, ranging from -9 to +18 dB. Results obtained with four normal-hearing listeners show that (1) for all masker locations and filtering conditions, localization accuracy remains unaffected by noise until 0-6 dB S/N and decreases at more adverse signal-to-noise ratios, (2) for all filtering conditions and at low signal-to-noise ratios, the effect of noise is greater when noise is presented at +/- 90 deg azimuth than at 0 deg azimuth, (3) the effect of noise is similar for all filtering conditions when noise is presented at 0 deg azimuth, and (4) when noise is presented at +/- 90 deg azimuth, the effect of noise is similar for the broadband and high-pass conditions, but greater for the low-pass condition. These results suggest that the low- and high-frequency cues used to localize sounds are equally affected when noise is presented at 0 deg azimuth. However, low-frequency cues are less resistant to noise than high-frequency cues when noise is presented at +/- 90 deg azimuth. When both low- and high-frequency cues are available, listeners base their decision on the cues providing the most accurate estimation of the direction of the sound source (high-frequency cues). Parallel measures of click detectability suggest that the poorer localization accuracy observed when noise is at +/- 90 deg azimuth may be caused by a reduction in the detectability of the signal at the ear ipsilateral to the noise.

Interaural asymmetry of hearing loss, Speech, Spatial and Qualities of Hearing Scale (SSQ) disabilities, and handicap

A series of comparative analyses is presented between a group with relatively similar degrees of hearing loss in each ear (n = 103: symmetry group) and one with dissimilar losses (n = 50: asymmetry group). Asymmetry was defined as an interaural difference of more than 10dB in hearing levels averaged over 0.5, 1, 2 and 4kHz. Comparison was focused on self-rated disabilities as reflected in responses on the Speech, Spatial and Qualities of Hearing Scale (SSQ). The connections between SSQ ratings and a global self-rating of handicap were also observed. The interrelationships among SSQ items for the two groups were analysed to determine how the SSQ behaves when applied to groups in whom binaural hearing is more (asymmetry) versus less compromised. As expected, spatial hearing is severely disabled in the group with asymmetry; this group is generally more disabled than the symmetry group across all SSQ domains. In the linkages with handicap, spatial hearing, especially in dynamic settings, was strongly represented in the asymmetry group, while all aspects of hearing were moderately to strongly represented in the symmetry group. Item intercorrelations showed that speech hearing is a relatively autonomous function for the symmetry group, whereas it is enmeshed with segregation, clarity and naturalness factors for the asymmetry group. Spatial functions were more independent of others in the asymmetry group. The SSQ shows promise in the assessment of outcomes in the case of bilateral versus unilateral amplification and/or implantation. Sumario Se presenta una serie de análisis comparativos entre un grupo con un grado de pérdida auditiva relativamente similar en cada oído (n = 103, grupo simétrico), y uno con pérdidas diferentes (n = 50, grupo asimétrico). La asimetría fue definida como una diferencia interaural de más de 10 dB en los niveles auditivos promediados en 0.5, 1, 2 y 4 kHz. La comparación se concentró en discapacidades auto-establecidas conforme se reflejaron en las respuestas de la Escala de Audición para el Lenguaje, la Audición Espacial y las Cualidades Auditivas (SSQ). Se observó también la conexión entre los puntajes del SSQ y la auto-evaluación global del impedimento. Se analizaron las interrelaciones entre los items de la SSQ para determinar el comportamiento de la SSQ cuando se aplica a grupos cuya audición binaural está más (asimetría) o menos comprometida. Como se esperaba, la audición espacial está severamente alterada en el grupo con asimetría; este grupo se muestra generalmente más discapacitado que el grupo simétrico, en todos los componentes de la SSQ. En su vinculación con la desventaja, la audición espacial, especialmente en contextos dinámicos, estuvo fuertemente representada en el grupo asimétrico, mientras que todos los aspectos de la audición fueron moderada a fuertemente representados en el grupo simétrico. La interacción de los items mostró que la captación del lenguaje es una función relativamente autónoma para el grupo simétrico, mientras que está relacionada con los factores de segregación, de claridad y de naturalidad para el grupo asimétrico. Las funciones espaciales fueron más independientes que las otras en el grupo asimétrico. La SSQ resulta prometedora en la evaluación de resultados en el caso de una amplificación bilateral versus unilateral, y/o en la implantación.

Linear and nonlinear hearing aid fittings – 2. Patterns of candidature

We studied candidature for linear, slow-acting AVC hearing aids, and fast-acting WDRC hearing aids in a within-subject within-device crossover design of 50 listeners with SNHL. Candidature dimensions include HTLs, ULLs, spectro-temporal and masking abnormalities, cognitive capacity, and self-reports and acoustic measures of auditory ecology. Better performance with linear fittings is associated with flatter audiograms, wider dynamic range, and smaller differences in dynamic range between low and high frequencies, and also with more restricted auditory lifestyles. Better performance with all nonlinear fittings is associated with more sloping audiograms, more restricted dynamic ranges, greater differences in dynamic range between low and high frequencies, and more varied auditory lifestyles. Differential performance between WDRC and AVC fittings is associated with patterns of variation in auditory ecology (rapid versus slow changes) and cognitive (high versus low) capacity. Differential performance between WDRC in two channels, and a hybrid with WDRC in a low-frequency and AVC in a high-frequency channel is associated with psychoacoustic tests of cochlear function (high susceptibility to spectral and temporal smearing, and high susceptibility to upward spread of masking respectively). Patterns of candidature include measures beyond auditory function in the domains of cognitive capacity and auditory ecology. Sumario Estudiamos cincuenta sujetos con SNHL buscando criterios de selección para adaptar auxiliares auditivos lineales, con AVC de acción lenta, o con WDRC de acción rápida, en un diseño cruzado que juzgaba variaciones intra-sujeto y con respecto al mismo dispositivo. Los criterios bajo estudio fueron HTL y ULL, anormalidades del espectro temporal y de enmascaramiento, habilidad cognitiva, y auto-reportes y medidas acústicas de ecología auditiva. Se asoció un mejor desempeño al hacer las adaptaciones lineales en sujetos con audiogramas más planos, con rangos dinámicos más amplios y con pequeñas diferencias en el rango dinámico entre frecuencias graves y agudas, así como con estilos de vida auditiva más restringidos. Un mejor desempeño en todas las adaptaciones no lineales se asoció con audiogramas con pendiente, con rangos dinámicos más restringidos, con mayores diferencias en el rango dinámico entre frecuencias graves y agudas, y con estilos auditivos de vida más variados. El desempeño diferencial entre adaptaciones con WDRC y con AVC se asoció con patrones de variación en la ecología auditiva (cambios rápidos vs. lentos), y con habilidad cognitiva (alta vs. baja). El desempeño diferencial entre WDRC en dos canales y un híbrido que utilizaba WDRC en una frecuencia baja, con un AVC en un canal de alta frecuencia se asoció con pruebas psicoacústicas de función coclear (una alta susceptibilidad a la disminución en la nitidez espectral y temporal, y alta susceptibilidad a una diseminación ascendente del enmascaramiento, respectivamente). Los patrones para selección de candidatos incluyen mediciones más allá de la función auditiva en el ámbito de la capacidad cognitiva y de la ecología auditiva.

The Glasgow Children's Benefit Inventory: A New Instrument for Assessing Health-Related Benefit after an Intervention

Most health-related quality-of-life measures make an assessment at a single point in time. Comparing results before and after an intervention is often difficult, because the difference measured is usually small compared with the variation between individuals. A retrospectively applied measure specifically worded to assess benefit would be very useful for clinical research. Such a measure exists for adults. We aimed to develop a similar measure for children. We chose potential items after reviewing existing health-related quality-of-life measures, published literature, and parental interviews. A draft questionnaire was given to a group of parents and modified. The resulting Glasgow Childrens Benefit Inventory (GCBI) comprised 24 questions on the consequences of a specified intervention on various aspects of the childs day-to-day life, without reference to any specific symptoms, and was worded to apply to children of any age. The questionnaire was mailed to the parents of all 1,777 children who had undergone tonsillectomy or ventilation tube insertion at one hospital during the period January 1998 to December 2001. There were 670 questionnaires returned. The GCBI scores correlated well with parental satisfaction with surgery and with estimates of technical success (residual sore throats, reported hearing impairment, ear infections). The questionnaire had high internal consistency. Factor analysis showed 4 dimensions in the pattern of responses relating to emotion, physical health, learning, and vitality. The GCBI is a means to retrospectively assess benefit after an intervention in children, and we have shown initial evidence of reliability and validity. Although not restricted to any branch of pediatric medicine, it is eminently suitable for use in pediatric otolaryngology.