Evaluation of nonlinear frequency compression: Clinical outcomes

Abstract

This study evaluated prototype multichannel nonlinear frequency compression (NFC) signal processing on listeners with high-frequency hearing loss. This signal processor applies NFC above a cut-off frequency. The participants were hearing-impaired adults (13) and children (11) with sloping, high-frequency hearing loss. Multiple outcome measures were repeated using a modified withdrawal design. These included speech sound detection, speech recognition, and self-reported preference measures. Group level results provide evidence of significant improvement of consonant and plural recognition when NFC was enabled. Vowel recognition did not change significantly. Analysis of individual results allowed for exploration of individual factors contributing to benefit received from NFC processing. Findings suggest that NFC processing can improve high frequency speech detection and speech recognition ability for adult and child listeners. Variability in individual outcomes related to factors such as degree and configuration of hearing loss, age of participant, and type of outcome measure.

Compressão de frequências no reconhecimento de fala de idosos com possíveis zonas mortas na cóclea

“…These results comply with studies conducted in subjects with and without ZMC, where audibility and recognition of monosyllables, consonants, plural and/or fricatives in silence showed better results with the use of techniques for lowering the frequencies 14,15,17,18,20 . It is also highlighted that the n of the present research was established by means of a sampling calculation, based in international articles, which, mostly have smaller samples 14,15,17,20 than the one from the study that is presented.…”

“…Moreover, considering the fact that the improvement is already seen in half of the subjects immediately, it is believed that the percentage of seniors benefiting from the use of CNLF in this study may, after a period of acclimatization, be even greater, as already observed in previous studies 14,33,34 .…”

“…By allowing the choice of a cutoff frequency (FC), from which the CNLF begins to act, this technology allows the preservation of natural formants of low frequencies, which are not affected by the compression, while maintaining the fundamental frequency of the human voice and causing less distortion of sounds 14,15 .…”

Índice Percentual de Identificação de Fonemas Fricativos: proposta para avaliação da compressão de frequências

“…These results concur with the researched literature (9,22,23,24,25) . In one study, the use of a frequency transposition algorithm in hearing impaired individuals with presence of dead regions in the cochlea, from 1.5 kHz, was efficient in the identification of the phoneme / ∫ / and, in general, there was no Identification of the other phonemes of the English language.…”

Effectiveness of Frequency-Lowering Hearing Aids and Electric Acoustic Stimulation Cochlear Implant for Treating People with a Severe-To-Profound High-Frequency Hearing Loss

“…Also, selected measurement tools may not have been sensitive enough to the subtle effects of NFC or LFT HAs, or not representative enough of real life. Other researchers used more analytical tasks, such as consonant recognition or /s/ detection [34][35][36][37]. We chose to use ecological outcome measures closer to real-life experience that are also considered clinical standard tests.…”