Measurement of brainstem speech-evoked potentials (BSEPs) and thier application in hearing assessment and speech processing technology

当声音到达耳朵时，微小的电脉冲通过大脑中不同的听觉中心传播，从而产生听觉。尽管这个过程仍然是个谜，但通过将电极贴在头皮上，我们可以无创地记录这些听觉中心的电活动。这种信号被称为听觉诱发电位，它使临床医生能够诊断听力问题并确定其在大脑中的起源。临床医生在这个测试中最常用的声音是一种简短的响亮的咔哒声，它的好处是作为一种简单的刺激，具有明确的诱发电位。然而，点击并不能提供足够的信息来评估听语音的能力。因此，人们对开发记录大脑对语言的电反应或语言诱发电位的测试越来越感兴趣。例如，我们最近发现语音诱发电位与元音音高的细微变化密切相关。事实上，这种大脑信号与语音波形非常相似，如果将其转换为声音并回放，就会被认为是可理解的语音。这意味着它允许我们“偷听”大脑内部的语言表达。

When sound reaches the ear, tiny electrical pulses propagate through the different auditory centres in the brain, resulting in the sensation of hearing. Although much about this process remains a mystery, by taping electrodes to the scalp we can non-invasively record the electrical activity in these auditory centres. This signal, called the Auditory-Evoked Potential, allows clinicians to diagnose hearing problems and localize their origin in the brain. The sound that clinicians most commonly use for this test is a brief loud click, which has the benefit of being a simple stimulus with a well-defined evoked potential. However, a click does not provide sufficient information to allow assessing the ability to hear speech. As a result, there is increasing interest in developing tests that record the brain's electrical response to speech, or the Speech-Evoked Potential. For example, we have recently shown that the Speech-Evoked Potential closely follows the fine variations in the pitch of a vowel. In fact, this brain signal is so similar to the speech waveform, if it is converted to a sound and played back, it is perceived as intelligible speech. This means that it allows us to "listen in" on the internal representation of speech within the brain.