National Acoustic Laboratories, Chatswood, Australia.
Int J Audiol. 2009 Nov;48(11):789-803. doi: 10.3109/14992020903036357.
Frequency-dependent microphone directionality alters the spectral shape of sound as a function of arrival azimuth. The influence of this on horizontal-plane localization performance was investigated. Using a 360 degrees loudspeaker array and five stimuli with different spectral characteristics, localization performance was measured on 21 hearing-impaired listeners when wearing no hearing aids and aided with no directionality, partial (from 1 and 2 kHz) directionality, and full directionality. The test schemes were also evaluated in everyday life. Without hearing aids, localization accuracy was significantly poorer than normative data. Due to inaudibility of high-frequency energy, front/back reversals were prominent. Front/back reversals remained prominent when aided with omnidirectional microphones. For stimuli with low-frequency emphasis, directionality had no further effect on localization. For stimuli with sufficient mid- and high-frequency information, full directionality had a small positive effect on front/back localization but a negative effect on left/right localization. Partial directionality further improved front/back localization and had no significant effect on left/right localization. The field test revealed no significant effects. The alternative spectral cues provided by frequency-dependent directionality improve front/back localization in hearing-aid users.
频率相关麦克风方向性会根据到达方位改变声音的频谱形状。研究了这种方向性对水平平面定位性能的影响。使用 360 度扬声器阵列和具有不同频谱特性的五个刺激，在 21 名听力受损的听众佩戴无助听器且无方向性、部分（1 和 2 kHz）方向性和全方向性时测量了定位性能。还评估了测试方案在日常生活中的应用。没有助听器，定位准确性明显低于规范数据。由于高频能量听不见，前后反转很明显。当使用全向麦克风辅助时，前后反转仍然很明显。对于低频强调的刺激，方向性对定位没有进一步影响。对于具有足够中频和高频信息的刺激，全方向性对前后定位有较小的正面影响，但对左右定位有负面影响。部分方向性进一步改善了前后定位，对左右定位没有显著影响。现场测试没有显示出显著效果。频率相关方向性提供的替代频谱线索可改善助听器使用者的前后定位。
