Brennan Marc, Souza Pamela
Speech and Hearing Sciences, University of Washington, 1417 NE 42nd St., Seattle, WA 98105, USA.
J Am Acad Audiol. 2009 Feb;20(2):119-27. doi: 10.3766/jaaa.20.2.5.
Hearing aid expansion is intended to reduce the gain for low-level noise. However, expansion can also degrade low-intensity speech. Although it has been suggested that the poorer performance with expansion is due to reduced audibility, this has not been measured directly. Furthermore, previous studies used relatively high expansion kneepoints.
This study compared the effect of a 30 dB SPL and 50 dB SPL expansion kneepoint on consonant audibility and recognition.
Eight consonant-vowel syllables were presented at 50, 60, and 71 dB SPL. Recordings near the tympanic membrane were made of each speech token and used to calculate the Aided Audibility Index (AAI).
Thirteen subjects with mild to moderate sensorineural hearing loss.
Expansion with a high kneepoint resulted in reduced consonant recognition. The AAI correlated significantly with consonant recognition across all conditions and subjects.
If consonant recognition is the priority, audibility calculations could be used to determine an optimal expansion kneepoint for a given individual.
助听器扩展旨在降低低强度噪声的增益。然而，扩展也会降低低强度语音的质量。尽管有人认为扩展时表现较差是由于可听度降低，但这尚未得到直接测量。此外，先前的研究使用的扩展拐点相对较高。
本研究比较了30 dB SPL和50 dB SPL扩展拐点对辅音可听度和识别的影响。
在50、60和71 dB SPL下呈现八个辅音-元音音节。对每个语音样本在鼓膜附近进行录音，并用于计算助听可听度指数（AAI）。
13名轻度至中度感音神经性听力损失患者。
高拐点扩展导致辅音识别率降低。在所有条件和受试者中，AAI与辅音识别率显著相关。
如果辅音识别是首要任务，可听度计算可用于确定特定个体的最佳扩展拐点。
