Effects of frequency compression and frequency transposition on fricative and affricate perception in listeners with normal hearing and mild to moderate hearing loss.

摘要: Objectives The authors have demonstrated that the limited bandwidth associated with conventional hearing aid amplification prevents useful high-frequency speech information from being transmitted. purpose of this study was to examine efficacy two popular frequency-lowering algorithms and one novel algorithm (spectral envelope decimation) in adults mild moderate sensorineural loss normal-hearing controls. Design Participants listened monaurally through headphones recordings nine fricatives affricates spoken by three women a vowel-consonant context. Stimuli were mixed speech-shaped noise at 10 dB SNR recorded Widex Inteo IN-9 Phonak Naida UP V behind-the-ear (BTE) aid. Frequency transposition (FT) is used nonlinear frequency compression (NFC) Naida. Both devices programmed lower frequencies above 4 kHz, but neither device could 6 7 kHz. Each tested under four conditions: lowering deactivated (FT-off NFC-off), activated (FT NFC), wideband (WB), fourth condition unique each WB constructed mixing first high-pass filtered versions source stimuli. For Inteo, consisted made same settings as first, noise-reduction feature (FT-off). Naida, except stimuli preprocessed algorithm, spectral decimation (SED), designed MATLAB, which allowed for more complete kHz input band. A follow-up experiment NFC Phonak's SP BTE, also greater range frequencies. Results hearing-impaired listeners, performance FT significantly worse compared other conditions. Consistent previous findings, listeners better than FT-off condition. In addition, SED conditions both NFC-off bandwidth. There no significant differences between WB, indicating improvements fricative identification obtained increasing can be using form compression. Significant most largely attributed an increase or decrease confusions phonemes /s/ /z/. experiment, NFC-off, replicating results SED. Furthermore, who performed poorly tended show improvement NFC. Conclusions Improvements chosen sensitive effects been forms (NFC SED) individuals loss. However, negative caution against population. indicate advantage extended reported here elsewhere applies (NFC/SED) when start ≥4