Glasgow Royal Infirmary, G31 2ER, Glasgow, UK.
Adv Exp Med Biol. 2013;787:303-10. doi: 10.1007/978-1-4614-1590-9_34.
It is often assumed that single sources of sound are perceived as being punctate, but this cannot be guaranteed, especially for hearing-impaired listeners. Any impairment that gives a reduction at the periphery in the accuracy of coding fine-scale temporal information must give a slight interaural jitter in the temporal information passed to higher centres, and so would be expected to lead to an effective reduction in the interaural coherence (IC) of any stimulus. This would lead to deficits in locating sounds, but deficits of imprecision, not inaccuracy. In turn, this implies that older hearing-impaired individuals should have a diminished perception of auditory space, affecting their abilities to perceive clear, concise, punctate spatial impressions or to separate sounds by location. The current work tested this hypothesis by using two separate visual-analogy methods to measure auditory source width for broadband sounds. In one method, the listener sketched the auditory image, a visual-description task, and for the other, the listener selected the closest one of a set of pre-drawn visual sketches (note that the first is an open-set experiment, whereas the second is a closed-set experiment). We found that older hearing-impaired listeners had increased difficulty in judging changes in interaural coherence, showing a corresponding insensitivity to auditory source width in the visual-analogy tasks.
人们通常认为单一来源的声音是点状的，但这不能保证，特别是对于听力受损的听众。任何在外周降低精细时间信息编码准确性的损伤，都会导致传递到更高中心的时间信息出现轻微的耳间抖动，因此预计会导致任何刺激的耳间相干性（IC）有效降低。这将导致定位声音的能力下降，但不是不准确，而是不精确。反过来，这意味着年龄较大的听力受损者的听觉空间感知能力会下降，影响他们感知清晰、简洁、点状空间印象的能力，或通过位置分离声音的能力。目前的工作通过使用两种独立的视觉类比方法来测量宽带声音的声源宽度，从而验证了这一假设。在一种方法中，听众画出听觉图像，这是一项视觉描述任务，而在另一种方法中，听众从一组预先绘制的视觉草图中选择最接近的一个（请注意，第一种方法是开放式实验，而第二种方法是封闭式实验）。我们发现，年龄较大的听力受损者在判断耳间相干性变化方面有更大的困难，在视觉类比任务中对声源宽度的变化表现出相应的不敏感。
