An Evidence-Based Systematic Review of Directional Microphones and Digital Noise Reduction Hearing Aids in School-Age Children With Hearing Loss

Abstract

Purpose The purpose of this evidence-based systematic review was to evaluate the efficacy of digital noise reduction and directional microphones for outcome measures of audibility, speech recognition, speech and language, and self- or parent-report in pediatric hearing aid users. Method The authors searched 26 databases for experimental studies published after 1980 addressing one or more clinical questions and meeting all inclusion criteria. The authors evaluated studies for methodological quality and reported or calculated p values and effect sizes when possible. Results A systematic search of the literature resulted in the inclusion of 4 digital noise reduction and 7 directional microphone studies (in 9 journal articles) that addressed speech recognition, speech and language, and/or self-or parent-report outcomes. No digital noise reduction or directional microphone studies addressed audibility outcomes. Conclusions On the basis of a moderate level of evidence, digital noise reduction was not found to improve or degrade speech understanding. Additional research is needed before conclusions can be drawn regarding the impact of digital noise reduction on important speech, language, hearing, and satisfaction outcomes. Moderate evidence also indicates that directional microphones resulted in improved speech recognition in controlled optimal settings; however, additional research is needed to determine the effectiveness of directional microphones in actual everyday listening environments.

Speech reception threshold benefits in cochlear implant users with an adaptive beamformer in real life situations

“…These multiple microphone beamformers have been incorporated successfully into hearing aids since the 1990s and two systematic reviews identified weak to moderate evidence of their effectiveness in improving speech perception in noise (Bentler, 2005;McCreery et al, 2012;Ricketts and Dhar, 1999;Ricketts and Henry, 2002). However, the first adaptive beamforming algorithms integrated into CI speech processors were not commercially introduced until 2005 (Spriet et al, 2007).…”

Head-Mounted Display Visualizations to Support Sound Awareness for the Deaf and Hard of Hearing

“…Modern devices employ sophisticated digital signal processing that often incorporates noise suppression, dynamic gain control, and directional microphones (e.g., [23,24]). The directional microphones amplify sound in front of the listener while limiting it from the sides and behind [19]; however, they generally do not improve the localization of sound without visual stimuli (speaker's face in view) [23]. For bilateral hearing aid users (both ears), each device works independently, which has destructive effects on the binaural cues necessary to locate sound [1].…”

Minimal Hearing Loss: From a Failure-Based Approach to Evidence-Based Practice

“…Children with severe to profound UHL are less likely to receive benefit from hearing aids (Kiese-Himmel, 2002;Updike, 1994). Another factor is background noise: hearing aids are less beneficial in noise than in quiet, although directional microphones may improve performance in noise (Ching et al, 2009;McCreery, Venediktov, Coleman, & Leech, 2012). Age at hearing aid fitting is another important factor, as hearing aids seem to be more beneficial if they are fit before the age of 5 to 6 years.…”