Speech Perception and Sound-Quality Rating with an Adaptive Nonlinear Frequency Compression Algorithm in Mandarin-Speaking Hearing Aid Users

Abstract

Background: Mandarin Chinese has a rich repertoire of high-frequency speech sounds. This may pose a remarkable challenge to hearing-impaired listeners who speak Mandarin Chinese because of their high-frequency sloping hearing loss. An adaptive nonlinear frequency compression (adaptive NLFC) algorithm has been implemented in contemporary hearing aids to alleviate the problem. Purpose: The present study examined the performance of speech perception and sound-quality rating in Mandarin-speaking hearing-impaired listeners using hearing aids fitted with adaptive NLFC (i.e., SoundRecover2 or SR2) at different parameter settings. Research Design: Hearing-impaired listeners' phoneme detection thresholds, speech reception thresholds, and sound-quality ratings were collected with various SR2 settings. Study Sample: The participants included 15 Mandarin-speaking adults aged 32 to 84 years old who had symmetric sloping severe-to-profound sensorineural hearing loss. Intervention: The participants were fitted bilaterally with Phonak Naida V90-SP hearing aids. Data Collection and Analysis: The outcome measures included phoneme detection threshold using the Mandarin Phonak Phoneme Perception test, speech reception threshold using the Mandarin hearing in noise test (M-HINT), and sound-quality ratings on human speech in quiet and noise, bird chirps, and music in quiet. For each test, five experimental settings were applied and compared: SR2-off, SR2-weak, SR2-default, SR2-strong 1, and SR2-strong 2. Results: The results showed that listeners performed significantly better with SR2-strong 1 and SR2-strong 2 settings than with SR2-off or SR2-weak settings for speech reception threshold and phoneme detection threshold. However, no significant improvement was observed in sound-quality ratings among different settings. Conclusions: These preliminary findings suggested that the adaptive NLFC algorithm provides perceptual benefit to Mandarin-speaking people with severe-to-profound hearing loss.