Bone-anchored hearing system, contralateral routing of signals hearing aid or cochlear implant: what is best in single-sided deafness?

Abstract

Purpose: The aim of the study was to compare long-term results after 1 year in patients with single-sided deafness (SSD) who were fitted with different hearing aids. The participants tested contralateral routing of signals (CROS) hearing aids and bone-anchored hearing systems (BAHS). They were also informed about the possibility of a cochlear implant (CI) and chose one of the three devices. We also investigated which factors influenced the choice of device.

Methods: Prospective study with 89 SSD participants who were divided into three groups by choosing BAHS, CROS, or CI. All participants received test batteries with both objective hearing tests (speech perception in noise and sound localisation) and subjective questionnaires.

Results: 16 participants opted for BAHS-, 13 for CROS- and 30 for CI-treatment. The greater the subjective impairment caused by SSD, the more likely patients were to opt for surgical treatment (BAHS or CI). The best results in terms of speech perception in noise (especially when sound reaches the deaf ear and noise the hearing ear), sound localization, and subjective results were achieved with CI.

Conclusion: The best results regarding the therapy of SSD are achieved with a CI, followed by BAHS. This was evident both in objective tests and in the subjective questionnaires. Nevertheless, an individual decision is required in each case as to which SSD therapy option is best for the patient. Above all, the patient's subjective impairment and expectations should be included in the decision-making process.

Keywords: Bone anchored hearing system; Cochlear implant; Contralateral routing of signals hearing aids hearing aid; SSQ; Single-sided deafness.

Fig. 1

Flowchart of study design: Of the initial 89 participants, 59 participants decided to continue the study. 16 participants underwent BAHS surgery, 13 chose CROS hearing aids and 30 participants underwent CI surgery. The times of the hearing tests and questionnaires are shown in the flowchart. BAHS bone-anchored hearing system, CI cochlear implant, CROS contralateral routing of signals, ECochG Electrocochleography, HHIE Hearing Handicap Inventory for Adults, HSM Hochmair–Schulz–Moser sentence test, IOI-HA International Outcome Inventory for Hearing Aids, OLSA Oldenburg sentence test, Promtest promontorial testing, SSQ Speech, Spatial and Qualities of Hearing Scale

Fig. 2

Box–Whisker plots of Hochmair–Schulz–Moser (HSM) sentence test: a S0N0 (S: speech; N: noise) presentation setup with speech and noise from the front. Group A: participants who chose BAHS; group B: participants who chose CROS; group C: participants who chose CI. b SssdNnh (ssd: single-sided deafness; nh: normal hearing) presentation setup with speech from the unilateral deaf side, noise from the normal hearing side. c SnhNssd presentation setup with speech from the normal hearing side, noise from the unilateral deaf side. BAHS bone-anchored hearing system, CI cochlear implant, CROS contralateral routing of signals

Fig. 3

Box–Whisker plots of localisation error: group A: participants who chose BAHS; group B: participants who chose CROS; group C: participants who chose CI. BAHS bone-anchored hearing system, CI cochlear implant, CROS contralateral routing of signals

Fig. 4

Box–Whisker plots of Speech, Spatial and Qualities of Hearing Scale (SSQ): group A: participants who chose BAHS; group B: participants who chose CROS; group C: participants who chose CI. a Speech understanding; b Spatial hearing; c Hearing quality: For a–c Unable to hear is represented by 0 and 10 means hears perfectly. BAHS bone-anchored hearing system, CI cochlear implant, CROS contralateral routing of signals