Towards a Unified Testing Framework for Single-Sided Deafness Studies: A Consensus Paper

Abstract

Background: While hearing aids for a contralateral routing of signals (CROS-HA) and bone conduction devices have been the traditional treatment for single-sided deafness (SSD) and asymmetric hearing loss (AHL), in recent years, cochlear implants (CIs) have increasingly become a viable treatment choice, particularly in countries where regulatory approval and reimbursement schemes are in place. Part of the reason for this shift is that the CI is the only device capable of restoring bilateral input to the auditory system and hence of possibly reinstating binaural hearing. Although several studies have independently shown that the CI is a safe and effective treatment for SSD and AHL, clinical outcome measures in those studies and across CI centers vary greatly. Only with a consistent use of defined and agreed-upon outcome measures across centers can high-level evidence be generated to assess the safety and efficacy of CIs and alternative treatments in recipients with SSD and AHL. Methods: This paper presents a comparative study design and minimum outcome measures for the assessment of current treatment options in patients with SSD/AHL. The protocol was developed, discussed, and eventually agreed upon by expert panels that convened at the 2015 APSCI conference in Beijing, China, and at the CI 2016 conference in Toronto, Canada. Results: A longitudinal study design comparing CROS-HA, BCD, and CI treatments is proposed. The recommended outcome measures include (1) speech in noise testing, using the same set of 3 spatial configurations to compare binaural benefits such as summation, squelch, and head shadow across devices; (2) localization testing, using stimuli that rove in both level and spectral content; (3) questionnaires to collect quality of life measures and the frequency of device use; and (4) questionnaires for assessing the impact of tinnitus before and after treatment, if applicable. Conclusion: A protocol for the assessment of treatment options and outcomes in recipients with SSD and AHL is presented. The proposed set of minimum outcome measures aims at harmonizing assessment methods across centers and thus at generating a growing body of high-level evidence for those treatment options.

Core Rehabilitation Outcome Set for Single Sided Deafness (CROSSSD) study: protocol for an international consensus on outcome measures for single sided deafness interventions using a modified Delphi survey

“…'Single-sided deafness' (SSD) is the name given to the condition in which there is normal or near-normal hearing in one ear and a severe to profound hearing impairment in the other ear [1]. SSD can be congenital, sudden or progressive.…”

The relationship between onset of single sided deafness and educational achievement

“…Hearing aids, Frequency Modulation (FM) systems that amplify the teacher's voice in class, CROS, and cochlear implants should be presented to patients. [16] The importance of protecting the healthy ear from loud noise should be explained, newborn screening for early diagnosis should be strengthened, and treatment should be started as early as possible, to increase the educational level of patients.…”

Sound Localization in Adults: Correlation with Varying Pure Tone Averages

“…Localization performance was quantified as the total root mean square error of the speaker angles. Therefore, a lower root mean square error indicates better localization skills (Van de Heyning et al, 2016). Percent derstanding of the specific study and the participants are probable.…”

“…As such, studies looking at patient group are plenty but normative data are insufficient for now (Dorman et al, 2016). Moreover, the pure tone averages (PTAs) used for examining correlation with sound localization error are various, even though there are sometimes guider consensus papers available (Kerber & Seeber, 2011), for instance, for unified testing framework in single-sided deafness studies, where PTA is defined as the mean thresholds at pure-tone frequencies of 500, 1,000, 2000, and 4,000 Hz (Van de Heyning et al, 2016). There is a study which used different PTAs for normal healthy group (125, 250, 500, 1,000, 2,000, and 4,000 Hz) and for bilateral hearing aided group (250, 500, 1,000, 2,000, and 4,000 Hz) (Dorman et al, 2016), though un-ASR 6,000 Hz) + (1 × 8,000 Hz)] / 9…”