Hearing Instruments for Unilateral Severe-to-Profound Sensorineural Hearing Loss in Adults: A Systematic Review and Meta-Analysis

Abstract

Objectives:A systematic review of the literature and meta-analysis was conducted to assess the nature and quality of the evidence for the use of hearing instruments in adults with a unilateral severe to profound sensorineural hearing loss.Design:The PubMed, EMBASE, MEDLINE, Cochrane, CINAHL, and DARE databases were searched with no restrictions on language. The search included articles from the start of each database until February 11, 2015. Studies were included that (a) assessed the impact of any form of hearing instrument, including devices that reroute signals between the ears or restore aspects of hearing to a deaf ear, in adults with a sensorineural severe to profound loss in one ear and normal or near-normal hearing in the other ear; (b) compared different devices or compared a device with placebo or the unaided condition; (c) measured outcomes in terms of speech perception, spatial listening, or quality of life; (d) were prospective controlled or observational studies. Studies that met prospectively defined criteria were subjected to random effects meta-analyses.Results:Twenty-seven studies reported in 30 articles were included. The evidence was graded as low-to-moderate quality having been obtained primarily from observational before-after comparisons. The meta-analysis identified statistically significant benefits to speech perception in noise for devices that rerouted the speech signals of interest from the worse ear to the better ear using either air or bone conduction (mean benefit, 2.5 dB). However, these devices also degraded speech understanding significantly and to a similar extent (mean deficit, 3.1 dB) when noise was rerouted to the better ear. Data on the effects of cochlear implantation on speech perception could not be pooled as the prospectively defined criteria for meta-analysis were not met. Inconsistency in the assessment of outcomes relating to sound localization also precluded the synthesis of evidence across studies. Evidence for the relative efficacy of different devices was sparse but a statistically significant advantage was observed for rerouting speech signals using abutment-mounted bone conduction devices when compared with outcomes after preoperative trials of air conduction devices when speech and noise were colocated (mean benefit, 1.5 dB). Patients reported significant improvements in hearing-related quality of life with both rerouting devices and following cochlear implantation. Only two studies measured health-related quality of life and findings were inconclusive.Conclusions:Devices that reroute sounds from an ear with a severe to profound hearing loss to an ear with minimal hearing loss may improve speech perception in noise when signals of interest are located toward the impaired ear. However, the same device may also degrade speech perception as all signals are rerouted indiscriminately, including noise. Although the restoration of functional hearing in both ears through cochlear implantation could be expected to provide benefits to speech perception, the inability to ...

Etiology of single-sided deafness and asymmetrical hearing loss

“…Although further evaluation using a large number of the patients is needed, recent case series have suggested that improvement in speech perception in noise and sound localization ability is possible, although the results varied from patient to patient [11]. Bone conduction devices and contralateral routing of sound systems are also worthy of consideration for SSD patients [6].…”

Unilateral Hearing Loss: Understanding Speech Recognition and Localization Variability—Implications for Cochlear Implant Candidacy

“…osseointegrated and contralateral routing of signal hearing devices), they do not restore hearing to the poor ear and therefore cannot provide access to binaural processing advantages. Cochlear implantation as a treatment for UHL is on the rise (Arndt et al 2011; Firszt, et al 2012; Kitterick et al 2016; Vermeire et al 2009; Zeitler et al 2015), yet little is known about factors that could impact performance or whether there is a group at risk for poor CI outcomes when hearing is normal or near-normal in one ear. Finally, more objective evaluations of monaural abilities are needed to inform future studies of outcomes provided by sensory devices.…”

One-Year Results for Patients with Unilateral Hearing Loss and Accompanying Severe Tinnitus and Hyperacusis Treated with a Cochlear Implant

“…There is a paucity of high-level evidence with many studies reporting on small numbers of patients from single centres. Few studies report generic quality of life measures, an essential requirement in many countries in order to make the case for reimbursement Cabral et al, 2016;Kitterick et al, 2016]. Where quality of life measures have been reported, disease specific measures showed a significant increase, but not in the generic measures [Knopke et al, 2017;Sladen et al, 2017].…”