AUDITORY TRAINING FOR PERSONS WITH DIFFICULTY UNDERSTANDING SPEECH IN NOISE

描述（由申请人提供）：即使对于听力正常的人来说，在不利的听力环境（如噪音）下的言语感知也比在安静环境下更困难。本研究计划的目标是评估一种新的评估和训练方案，以帮助那些在噪音中理解语言有困难的人。两个目标人群是非母语（L2）英语人士和母语英语人士，他们患有各种形式的听觉处理障碍（一般称为APD）。据报道，这两组人都有类似的噪音问题，但之前的研究提出了几种不同的潜在机制。对于第二语言使用者来说，人们一直认为他们对噪音的感知问题主要是由于来自母语的声音干扰，而被噪音掩盖使其恶化。也就是说，他们的问题是使用上下文无关（自底向上）处理的能力减弱。为了弥补这一点，这个群体倾向于严重依赖上下文信息（自上而下的处理）。APD组的潜在机制尚不清楚。虽然有些人认为噪音的困难是由听觉时间编码受损引起的，但其他人认为这一群体也可能有较差的语音意识。尽管语言感知模型在这些技能如何在正常的母语人士中组合工作方面有所不同，但似乎一致认为自下而上的处理是自动的，而自上而下的处理可能更费力，并受到自下而上处理完整性的影响。因此，过度使用自顶向下的处理来弥补自底向上处理的不足可能会阻碍语音感知的整体效率。拟议的研究计划将测试以下三个假设：1)L2使用者和母语APD群体在噪音中感知语音的困难与声学-语音意识受损有关（即自下而上的处理）；2)自下而上处理技能的提高将减少对上下文信息的依赖（即自上而下的处理），从而有助于在噪声环境下的语音感知；3)自下而上的显性训练将提高两组人在噪声环境下的语音感知能力。这些假设将通过三个目标进行检验。在Aim 1中，听者使用自上而下和自下而上的加工来理解噪音中的语音，将通过比较孤立词和句子中的词的感知来研究。在目标2中，我们将通过在目标1中选择的一组二语听者来评估一种新的自下而上的处理训练程序，该训练程序使用很少上下文信息的句子。在目标3中，该培训程序将由APD听众小组进行评估。拟议的研究是为APD患者和英语第二语言者建立有效和高效的评估和培训方案的重要初始阶段。它也有望为在噪音中理解语音困难的个体所使用的潜在感知机制提供重要的新信息。

DESCRIPTION (provided by applicant): Speech perception in adverse listening environments (e.g., noise) is more difficult than in quiet even for individuals with normal hearing. The goal of the proposed research program is to evaluate a novel assessment and training protocol for individuals who experience difficulty understanding speech in noise. The two target populations are non-native (L2) English speakers and native English speakers with various forms of auditory processing disorders (referred to generically as APD). Similar problems in noise have been reported for both groups, but previous studies have suggested several different underlying mechanisms. For L2 speakers, it has been assumed that their perceptual problems in noise are due primarily to acoustic-phonetic interference from their native language worsened by masking from noise. That is, their problem is a diminished ability to use context-independent (bottom-up) processing. To compensate, this group tends to rely heavily on the contextual information (top-down processing). The underlying mechanisms for APD group are not clearly understood. While some argue that difficulties in noise are caused by impaired auditory temporal coding, others have suggested that this group may also have poor acoustic-phonetic awareness. Although models of speech perception differ in terms of how these skills work in combination in normal native speakers, there seems to be agreement that bottom-up processing is automatic, whereas top-down processing can be more effortful and is influenced by the integrity of bottom-up processing. Thus the overuse of top-down processing to compensate for poor bottom-up processing may impede overall efficiency of speech perception. The proposed research program will test the following three hypotheses: 1) that the difficulties perceiving speech in noise for both L2 speakers and native APD groups are related to compromised acoustic-phonetic awareness (i.e., bottom-up processing); 2) that an improvement in bottom-up processing skills will aid speech perception in noise by reducing the need to rely as heavily on contextual information (i.e., top-down processing); and 3) that explicit training in bottom-up processing will improve speech perception in noise for both groups. These hypotheses will be tested through three aims. In Aim 1, listeners' use of top-down and bottom-up processing to understand speech in noise will be investigated by comparing perception of isolated words and words in sentences. In Aim 2, a novel bottom-up processing training procedure using sentences with little contextual information will be evaluated with a subgroup of L2 listeners selected under Aim 1. In Aim 3, this training procedure will be evaluated with a subgroup of APD listeners. The proposed research is an important initial stage in establishing an effective and efficient assessment and training protocol for individuals with APD and for L2 speakers of English. It is also expected to provide important new information on the underlying perceptual mechanisms used by individuals who experience difficulty understanding speech in noise. Relevance: The ultimate goal of this research project is to develop a protocol for the assessment and training of speech perception for individuals who experience marked difficulty understanding speech in noise. The efficacy of a novel auditory training protocol will be evaluated in two groups of individuals who are known to have difficulty understanding speech in noise: English speaking children with auditory processing disorders and/or language-based learning disabilities and adult L2 speakers of English.