Cochlear Limited, Level 1, 174 Victoria Parade, East Melbourne 3002, Victoria, Australia.
J Acoust Soc Am. 2012 Jan;131(1):327-36. doi: 10.1121/1.3665990.
Noise reduction in cochlear implants has achieved significant speech perception improvements through spectral subtraction and signal-to-noise ratio based noise reduction techniques. Current methods use gain functions derived through mathematical optimization or motivated by normal listening psychoacoustic experiments. Although these gain functions have been able to improve speech perception, recent studies have indicated that they are not optimal for cochlear implant noise reduction. This study systematically investigates cochlear implant recipients' speech perception and listening preference of noise reduction with a range of gain functions. Results suggest an advantageous gain function and show that gain functions currently used for noise reduction are not optimal for cochlear implant recipients. Using the cochlear implant optimised gain function, a 27% improvement over the current advanced combination encoder (ACE) stimulation strategy in speech weighted noise and a 7% improvement over current noise reduction strategies were observed in babble noise conditions. The optimized gain function was also most preferred by cochlear implant recipients. The CI specific gain function derived from this study can be easily incorporated into existing noise reduction strategies, to further improve listening performance for CI recipients in challenging environments.
通过频谱减法和基于信噪比的降噪技术，在人工耳蜗中降低噪声已经实现了显著的语音感知改善。当前的方法使用通过数学优化得出的增益函数，或者受到正常听力心理声学实验的启发。尽管这些增益函数已经能够改善语音感知，但最近的研究表明，它们对于人工耳蜗降噪并不是最佳的。本研究系统地研究了人工耳蜗植入者在一系列增益函数下的语音感知和降噪的听力偏好。结果表明存在一个有利的增益函数，并表明当前用于降噪的增益函数对于人工耳蜗植入者来说不是最佳的。使用优化后的人工耳蜗增益函数，在语音加权噪声中比当前的高级组合编码器（ACE）刺激策略提高了 27%，在噪声环境中比当前的降噪策略提高了 7%。该优化后的增益函数也最受人工耳蜗植入者的欢迎。本研究中得出的特定于人工耳蜗的增益函数可以很容易地整合到现有的降噪策略中，从而进一步提高人工耳蜗植入者在挑战性环境中的听力表现。
