Aq Summerfield

Effectiveness of computer-based auditory training for adult users of cochlear implants

Abstract Cochlear implantation is effective at restoring partial hearing to profoundly deaf adults, but not all patients receive equal benefit. The present study evaluated the effectiveness of a computer-based self-administered training package that was designed to improve speech perception among adults who had used cochlear implants for more than three years. Eleven adults were asked to complete an hour of auditory training each day, five days a week, for a period of three weeks. Two training tasks were included, one based around discriminating isolated words, and the other around discriminating words in sentences. Compliance with the protocol was good, with eight out of eleven participants completing approximately 15 hours of training, as instructed. A significant improvement of eight percentage points was found on a test of consonant discrimination, but there were no significant improvements on sentence tests or on a test of vowel discrimination. Self-reported benefits were variable and generally small. Further research is needed to establish whether auditory training is particularly effective for identifiable sub-groups of cochlear-implant users. Sumario La implantación coclear es efectiva para restaurar desde una alteración parcial de la audición hasta una sordera profunda en adultos, pero no todos los pacientes reciben el mismo beneficio. El presente estudio evalúa la efectividad de un paquete de entrenamiento computarizado y auto-administrado que se diseñó para mejorar la percepción del lenguaje en adultos que han utilizado implantes cocleares por más de tres años. Se le pidió a once adultos que completaran una hora de entrenamiento auditivo cada día, cinco dóas por semana, por un peróodo de tres semanas. Se incluyeron dos tareas de entrenamiento, una basada en la discriminación de palabras aisladas y la otra en discriminación de palabras en medio de frases. El cumplimiento del protocolo fue bueno, con ocho de quince participantes que completaron aproximadamente 15 horas de entrenamiento, como se instruyó. Se encontró una mejoría significativa de ocho puntos porcentuales en una prueba de discriminación de consonantes, pero no existió una mejoría significativa en las pruebas de frases o en la prueba de discriminación de vocales. Los beneficios auto-reportados fueron variables y generalmente pequeños. Se requiere investigación adicional para establecer si el entrenamiento auditivo es particularmente efectivo en subgrupos identificables de usuarios de implantes cocleares.

Hearing-impaired children in the United Kingdom, II: Cochlear implantation and the cost of compulsory education

Objective: The objective of this study was to estimate the impact of cochlear implantation on the cost of compulsory education of hearing-impaired children in the United Kingdom. Study Design: In a cross-sectional survey, teachers were asked to report the school placement of, and amount of support provided to, a representative sample of hearing-impaired children. Costs of school placement were obtained from published sources. Costs of support were calculated from a survey of 11 special education services. The annual education cost (in &U20AC;uros at 2001/2002 levels) of each child was calculated by summing the placement and support costs. Linear regression analyses calculated the association between annual education cost and possession of an implant while controlling nine other variables: average (unaided, preoperative) hearing level (AHL), age at onset of hearing impairment, age, gender, the number of additional disabilities, parental occupational skill level, ethnicity, parental hearing status, and academic achievement. Results: Data were received for 2241 children, 383 of whom had cochlear implants. Mean annual education cost ranged from &U20AC;15,745 for children with moderate hearing impairments to &U20AC;30,071 for nonimplanted children with profound hearing impairments and was &U20AC;28,058 for implanted children. A lower annual education cost was associated with a more favorable AHL, a later age at the onset of hearing impairment, female gender, a younger age, fewer additional disabilities, and a higher level of academic achievement. When these variables were controlled, costs were lower on average for implanted compared with nonimplanted children for the subset of children whose AHLs exceeded 111 dB. At the mean AHL of the implanted children (115 dB), implantation was associated with a reduction of &U20AC;3105 (95% confidence interval, &U20AC;1105 to &U20AC;5106) in annual education costs. Conclusions: Pediatric cochlear implantation is sufficiently effective to influence resource-allocation decisions in the education sector. The health-service cost of implantation is partly offset by savings in the cost of education. These savings occur without detriment to academic achievements.

The AB-York crescent of sound: An apparatus for assessing spatial-listening skills in children and adults

Abstract Modern health services need efficient tools for measuring outcomes from interventions, that is, tools of proven efficacy which make minimal demands on the time of clinicians in learning to administer tests and in interpreting results. This paper describes an apparatus designed to meet those requirements. The apparatus administers performance tests of spatial listening for children and adults with unilateral and bilateral cochlear implants. The apparatus was designed with guidance from clinicians. It possesses three key attributes: it is simple to use; the results of tests are scored automatically and are compared with reference data; the apparatus generates comprehensive personalized reports for individual participants that can be included in clinical notes. This paper describes the apparatus and reports results of a test measuring spatial release from masking of speech which illustrates the compatibility between the new apparatus and an older apparatus with which the reference data were gathered.

Bilateral cochlear implantation for hearing-impaired children: criterion of candidacy derived from an observational study.

Objectives: Policy-makers have struggled to define the minimum degree of hearing impairment at which children should be offered cochlear implants rather than the less invasive alternative of acoustic hearing aids. This study compared outcomes for children with bilateral cochlear implants and children with bilateral hearing aids, to determine a criterion of candidacy for pediatric bilateral cochlear implantation. Design: This observational study measured the listening skills of children who received routine audiological care in the United Kingdom. Participants were recruited from hospitals, educational services, and charities. Eligibility criteria included a diagnosis of hearing impairment before 31 months of age and pure-tone thresholds greater than or equal to 50 dB HL at 2 and 4 kHz bilaterally. Seventy-one children participated, aged 46 to 86 months (mean 64 months). Twenty-eight children used bilateral implants provided in a simultaneous surgery; 43 used bilateral digital hearing aids. The two groups of children were demographically similar in variables that predict outcomes for children with hearing impairment. Children’s ability to understand speech was measured using closed-set tests of word discrimination in three conditions: in quiet, in pink noise, and in two-talker babble. For each listening test, an actuarial method was used to compare the distribution of scores from children with cochlear implants and children with hearing aids. The aim was to calculate the unaided pure-tone average (PTA) hearing level at which a child has odds of 4:1 of a better outcome with implants than with hearing aids. The PTA associated with odds of 4:1 has been used previously to define criteria of candidacy for implantation. The main analyses used a four-frequency PTA (mean of unaided thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear). Additional analyses used a three-frequency PTA (0.5, 1, and 2 kHz) and two-frequency PTA (2 and 4 kHz). Results: Odds of 4:1 of a better outcome with implants were associated with a four-frequency PTA of 79, 86, and 76 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 80 dB HL. It can be difficult to measure a four-frequency PTA in young children, but a two-frequency PTA typically can be measured. Odds of 4:1 were associated with a two-frequency PTA of 83, 92, and 80 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 85 dB HL. Conclusions: Children with an unaided four-frequency PTA of 80 dB HL or poorer in both ears should be considered candidates for bilateral cochlear implantation. In cases where a four-frequency PTA cannot be measured, the criterion of candidacy should be a two-frequency PTA of 85 dB HL or poorer in both ears. If adopted by policy-makers, these recommendations would expand the provision of cochlear implants among children in England and Wales.

Hearing-impaired children in the United Kingdom, III: cochlear implantation and the economic costs incurred by families.

Objectives: This article addresses two questions. First, are there differences in the economic costs incurred by families of hearing-impaired children depending on whether or not children have cochlear implants? Second, are these differences important when assessed from the perspective of society? Methods: In a cross-sectional survey, parents of a representative sample of hearing-impaired children provided data about annual resources used by the family because of their child’s hearing impairment. The data yielded estimates of two variables: out-of-pocket expenditure and time away from normal activities by parents. The economic cost of the two variables was estimated in &U20AC;uros (&U20AC;) at 2001/2 price levels, and summed to estimate the overall economic cost incurred by the family. Linear regression was used to estimate the association between costs and implantation, while controlling for average (unaided, preoperative) hearing level, age at onset of hearing impairment, age, gender, the number of additional disabilities, parental occupational skill level, ethnicity, and parental hearing status. The cumulative economic cost incurred by the families of implanted children, between implantation and age 16 yr, was calculated from estimates of the overall economic cost associated with implantation and compared with estimates of the incremental health-sector cost of implantation. Results: Data were provided by the families of 2858 children, 468 of whom had received a cochlear implant. Compared with the families of nonimplanted children, out-of-pocket expenditure was estimated to be significantly higher for families when children were implanted before the age of 5 yr and had used their implant for less than 2 yr, as was lost productivity when children had used their implants for less than 2 yr. Overall economic cost was estimated to be significantly higher for the families of implanted children who had used their implants for less than 2 yr. The cumulative economic cost was estimated to be &U20AC;3355 for a family whose child was implanted at age 3 yr and &U20AC;949 for a child implanted at age 6 yr. These costs correspond, at most, to 3% of the incremental health-sector costs of implantation. Conclusions: Compared with families of nonimplanted children, families of implanted children incur additional costs in the 2 yr after implantation. These costs are small in relation to the health-sector costs of providing implantation.

Use of vocalic information in the identification of /s/ and /sh/ by children with cochlear implants.

Objective When a syllable such as “sea” or “she” is spoken, listeners with normal hearing extract evidence of the fricative consonant from both the fricative noise and the following vocalic segment. If the fricative noise is made ambiguous, listeners may still perceive “s” or “sh” categorically, depending on information in the vocalic segment. Do children whose auditory experience comes from electrical stimulation also display this effect, in which a subsequent segment of speech disambiguates an earlier segment? Design Unambiguous vowels were appended to ambiguous fricative noises to form tokens of the words “she,” “sea,” “shoe,” and “Sue.” A four-choice identification test was undertaken by children with normal hearing (N = 29), prelingually deaf children with the Nucleus Spectra-22 implant system using the SPEAK coding strategy (N = 13), postlingually deafened adults with the same implant system (N = 26), and adults with normal hearing (N = 10). The last group undertook the test before and after the stimuli were processed to simulate the transformations introduced by the SPEAK coding strategy. Results All four groups made use of vocalic information. Simulated processing reduced the use made by normal-hearing adults. Implanted subjects made less use than the other groups, with no significant difference between implanted children and implanted adults. The highest levels of use by implanted subjects were within one standard deviation of the mean level displayed when normal-hearing adults listened to processed stimuli. Analyses showed that the SPEAK strategy distorted formant contours in the vocalic segments of the stimuli in ways that are compatible with the errors of identification made by implanted subjects. Conclusions Some children with implants can extract information from a following vowel to disambiguate a preceding fricative noise. The upper limit on this ability may be set by distortions introduced by the implant processor, rather than by the auditory experience of the child.

Health service costs of paediatric cochlear implantation: influence of the scale and scope of activity.

The health service cost of paediatric cochlear implantation (CI) varies among hospitals in the UK. The purpose of this study was to determine whether the variation is associated with differences in the scale and scope of activity in CI programmes. The health service cost of CI was estimated for 908 children implanted in 12 hospitals between 1989 and 1998. Annual levels of activity in implanting children and adults were monitored in the same hospitals. Costs of paediatric CI were lower in hospitals implanting larger numbers of children and adults, thereby benefiting from economies of scale and scope, respectively. These economies arose from lower per-child staff costs in larger programmes, and were estimated to be exhausted when a hospital implanted more than nine children and more than 20 adults each year. Accommodating increased numbers of children in an existing programme is predicted to cost less than setting up a new programme. Sumario El costo para los servicios de salud de la implantación coclear pediátrica (CI) varía entre los hospitales del Reino Unido. El propósito de este estudio fue determinar si la variación se asocia con diferencias en la escala y el ámbito de actividad en los programas de CI. El costo para el servicio de salud de un IC se estimó en 908 nin˜os implantados en 12 hospitales, entre 1989 y 1998. Se monitorearon los niveles anuales de actividad en implantación de nin˜os y adultos en los mismos hospitales. El costo de los CI pediátricos fue menor en aquellos hospitales que implantaban grandes números de nin˜os y adultos, beneficiándose de economías de escala y de ámbito, respectivamente. Estas economías surgieron de menores costos de personal por nin˜o en los programas más grandes y se estimó que se agotaban cuando un hospital implantó más de nueve nin˜os y más de 20 adultos por an˜o. El acomodar un número creciente de nin˜os en un programa existente predice un menor costo que establecer un nuevo programa.