Evaluation of a Frequency-Lowering Algorithm for Adults With High-Frequency Hearing Loss

Abstract

The objective was to determine the effects of a frequency-lowering algorithm (frequency composition, Fcomp) on consonant identification, word-final /s, z/ detection, the intelligibility of sentences in noise, and subjective benefit, for people with high-frequency hearing loss, including people with dead regions (DRs) in the cochlea. A single-blind randomized crossover design was used. Performance with Bernafon Acriva 9 hearing aids was compared with Fcomp off and Fcomp on. Participants wore the hearing aids in each condition in a counterbalanced order. Data were collected after at least 8 weeks of experience with a condition. Outcome measures were audibility, scores from the speech perception tests, and scores from a questionnaire comparing self-perceived hearing ability with Fcomp off and Fcomp on. Ten adults with mild to severe high-frequency hearing loss (seven with extensive DRs, one with patchy or restricted DRs, and two with no DR) were tested. Fcomp improved the audibility of high-frequency sounds for 6 out of 10 participants. There was no overall effect of Fcomp on consonant identification, but the pattern of consonant confusions varied across conditions and participants. For word-final /s, z/ detection, performance was significantly better with Fcomp on than with Fcomp off. Questionnaire scores showed no differences between conditions. In summary, Fcomp improved word-final /s, z/ detection. No benefit was found for the other measures.

Comparison of Frequency Transposition and Frequency Compression for People With Extensive Dead Regions in the Cochlea

“…However, the pattern of confusions differed across conditions. This is consistent with previous research using frequency lowering (Alexander, 2016; Ellis & Munro, 2015; Glista et al., 2009; Kokx-Ryan et al., 2015; Posen et al., 1993; Robinson et al., 2007, 2009; Salorio-Corbetto et al., 2017a; Simpson et al., 2006). Bayesian statistical methods and tools developed by Leijon et al.…”

“…DRs were characterized using the same methods and equipment as described by Salorio-Corbetto et al. (2017a, 2017b).…”

The Use of Frequency Lowering Technology in the Treatment of Severe-to-Profound Hearing Loss: A Review of the Literature and Candidacy Considerations for Clinical Application

“…Furthermore, it has been recommended that consideration be given to the use of FL for listeners diagnosed with DRs at high frequencies. 32 Research in this area is divided into studies that have incorporated information of DRs in the FL fitting process 10,34,35 and those that have not. 3,4,6 The fitting methods, type of FL technology used, and participant groups all differ across the reported studies, making conclusions related to fitting FL with DRs difficult.…”

“…15 This type of lowering has been evaluated in research including listeners with cochlear DRs. 10 Like frequency transposition, some recent signal processors allow the conventional hearing aid bandwidth to be preserved (as a fitting option) and mixed with the frequency lowered signal. This effectively adds back the entire passband of sound available for a given device to be used in the fitting process.…”

“…Considering the studies reporting benefit with FL in hearing aid trials with adult and child listeners, many have included listeners with sloping hearing loss of a severe or profound degree in the high frequencies. [1][2][3][4][5][6][7][8][9][10] This literature also suggests that some listeners may not benefit from FL and may even experience adverse speech perception effects. [11][12][13] In addition to speech perception, some of the more recent studies have focused on how FL may affect outcomes of sound quality and objective measures of listening effort for listeners with high-frequency hearing loss.…”