Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial

Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. Discussion This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Trial registration Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013

Management of single-sided deafness with the bone-anchored hearing aid

OBJECTIVES: The benefits of the bone-anchored hearing aid (BAHA) for rehabilitation of conductive and mixed hearing loss are well established. Recently, the BAHA was used to rehabilitate patients with single-sided deafness (SSD). In this study, the benefits of the BAHA in SSD are presented. STUDY DESIGN: Case series with planned data collection. SETTING: Tertiary referral center. SUBJECTS AND METHODS: Twenty-one consecutive adult patients with SSD underwent single-stage BAHA implantation on the side of deafness. Testing in sound field was performed using the hearing-in-noise test (HINT) in both unaided and aided conditions. Speech and noise signals were delivered through two speakers oriented in two test paradigms. The outcomes were expressed as signal-to-noise (S/N) ratios. Subjective benefit analyses were determined through two questionnaires: the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Glasgow Hearing Aid Benefit Profile (GHABP). RESULTS: All subjects demonstrated significant improvement in speech reception thresholds with the HINT using the BAHA, especially with the 90/270 speaker paradigm, in which the mean improvement over the unaided condition was 5.5 dB SPL (range, 2.0-11.0 dB; P=0.00001). Qualitative subjective outcome measures demonstrated additional benefits. CONCLUSION: In SSD patients, the BAHA provides significant subjective benefits and improves speech understanding in noise

Measuring the understanding of sentences by hearing-impaired children: comparison with connected discourse ratings

Measuring the understanding of connected speech by hearing-impaired children is desirable if an appropriate rehabilitative or special educational program is to be implemented or monitored. This study was undertaken to explore the potential of a Cantonese version of the Helen sentence test as a measure of understanding connected speech by a group of 54 mildly to profoundly hearing-impaired children, and to compare the results from this sentence test with those achieved by the same children on a connected discourse lest. The effects of two different hearing aid frequency responses and two noise conditions on the results from both tests were also examined. Findings from the present study revealed that the Helen sentence test could be successfully adapted For use with Cantonese-speaking hearing-impaired children in Hong Kong. When compared to the connected discourse test, the modified Helen test produced significantly higher scores and was more sensitive to changes in noise level, especially for the severely and profoundly hearing-impaired children