Bone-Anchored Hearing Aid in Unilateral Inner Ear Deafness: A Study of 20 Patients

Abstract

Objective: To evaluate the benefit of a bone-anchored hearing aid (BAHA) contralateral routing of sound (CROS) in 20 patients with unilateral inner ear deafness. Subjects: 21 patients were recruited; 15 had undergone acoustic neuroma surgery and 6 patients had unilateral profound hearing loss due to other causes; 1 patient was excluded. Only patients with thresholds of better than 25 dB HL (500–2000 Hz) and an air-bone gap of less than 10 dB in the best ear were included. Methods: Evaluation involved audiometric measurements before intervention, when fitted with a conventional CROS and after implementation and quantification of the patients’ subjective benefit with a hearing aid-specific instrument: the Abbreviated Profile of Hearing Aid Benefit (APHAB). Results: Lateralization scores were not significantly different from chance (50%) in any of the three conditions. Measurements of speech perception in noise showed an increase in the signal to noise ratio (S/N ratio) with the conventional CROS (p = 0.001) and with the BAHA CROS compared to the unaided condition when speech was presented at the front with noise on the poor hearing side. On the other hand, a lower S/N ratio was seen with the BAHA CROS (p = 0.003) compared to the unaided situation when noise was presented at the front with speech on the poor hearing side. The patient outcome measure (APHAB) showed improvement, particularly with the BAHA CROS. Conclusions: The poor sound localization results illustrate the inability of patients with unilateral inner ear deafness to localize sounds. The speech-in-noise measurements reflect the benefit of a BAHA CROS in lifting the head shadow while avoiding some of the disadvantages of a conventional CROS. The benefit of the BAHA CROS was most clearly reflected in the patients’ opinion measured with the APHAB.

Benefit of a Contralateral Routing of Signal Device for Unilateral Cochlear Implant Users

“…12; SNR S0N90: 23.5 dB). In other studies that evaluated the effect of a bone-anchored hearing aid in singlesided deafness (which is a similar situation to our 1-sided CI patients), deterioration in situation S0N90 was -0.7 to -2.5 dB [Bosman et al, 2003;Hol et al, 2004;Linstrom et al, 2009;Pfiffner et al, 2011]. Our value of -0.66 lies at the bottom end of the scale of the quoted studies.…”

Amplification Considerations for Children With Minimal or Mild Bilateral Hearing Loss and Unilateral Hearing Loss

“…[58][59][60] However, improved recognition for either device over unaided conditions are normally minimal except in cases where the speech is directed to the aided ear and where the noise is from some other direction. Negative effects are often observed when the noise is coming from the aided side.…”

Baha-Mediated Rehabilitation of Patients with Unilateral Deafness: Selection Criteria

“…The majority of these studies either focused on satisfaction following Baha-mediated rehabilitation or on comparing satisfaction resulting from various means of rehabilitation for unilateral deafness [Hol et al, 2010]. Since 2005, we have been offering Baha hearing aids for treating unilateral deafness because the literature suggests it is an effective means for rehabilitating this condition [Niparko et al, 2003;Hol et al, 2004Hol et al, , 2005Wazen et al, 2005]. We have implemented a series of preoperative audiometric tests adapted from the selection method proposed by Vaneecloo et al [2000] in order to show our patients the type of hearing improvement they can expect from Baha.…”