Abstract:
The perception of a talker\'s head orientation is an ecologically relevant task. Humans are able to discriminate changes in talker head orientation using acoustic cues. Factors that may influence measures of this ability have not been well characterized. Here, we examined the minimum audible change in head orientation cues (MACHO) using diotic stimuli. The effects of several factors were tested: talker and gender, stimulus bandwidth (full-band vs low-pass filtered at 8 or 10 kHz), transducer (loudspeaker vs headphone), stimulus uncertainty (interleaved vs blocked presentation of four talkers), and vocal production mode (speech vs singing). The best performance of ∼41° was achieved for full-band, blocked presentation of speech over a loudspeaker. Greater stimulus uncertainty (interleaved presentation) worsened the MACHO by 26%. Bandlimiting at 8 and 10 kHz worsened performance by an additional 22% and 14%, respectively. At equivalent overall sound levels, performance was better for speech than for singing. There was some limited evidence for the transducer influencing the MACHO. These findings suggest the MACHO relies on multiple factors manipulated here. One of the largest, consistent effects was that of talker, suggesting head orientation cues are highly dependent on individual talker characteristics. This may be due to individual variability in speech directivity patterns.
摘要:
对说话者头部方向的感知是一项与生态相关的任务。人类能够使用声学线索来区分说话者头部取向的变化。可能影响这种能力测量的因素尚未得到很好的表征。这里,我们使用双向刺激检查了头部方向提示(MACHO)的最小听觉变化。测试了几个因素的影响:说话者和性别,刺激带宽(全频带与低通滤波在8或10kHz),换能器(扬声器与耳机),刺激的不确定性(交错的和四个说话者的阻塞的表达),和声乐制作模式(演讲与歌唱)。全波段的最佳性能为〜41°,通过扬声器阻止演讲。更大的刺激不确定性(交错呈现)使MACHO恶化了26%。8和10kHz的带宽限制使性能下降了22%和14%,分别。在同等的总声级下,演讲比唱歌更好。传感器影响MACHO的证据有限。这些发现表明,MACHO依赖于这里操纵的多种因素。最大的,一致的效果是健谈者的效果,这表明头部取向线索高度依赖于个体说话者的特征。这可能是由于语音指向性模式的个体可变性。