Phonetic adaptation as (near) rational learning in a variable environment

描述（由申请人提供）：理解语音是一项非凡的能力：听者需要从一个以他们无法控制的速度展开的瞬态和噪声信号中提取异步分布的语音特征。尽管口语处理在普通人群中普遍成功，但5%的一年级学生入学时患有某种语言障碍，而这种障碍不能用听力障碍来解释。此外，一旦语言系统获得成功，它很容易受到伤害或中风的侮辱（美国有100万成年人患有某种形式的失语症）。语音理解必须克服的最大挑战之一是，说话者在如何准确地理解相同的预期声音方面存在差异，因此一个说话者的“桃子”可能与另一个说话者的“海滩”在物理上无法区分。研究表明，我们通过快速适应说话者特定的发音来克服这一挑战。更全面地了解这些适应过程背后的感知和计算能力，对于促进对正常和异常语言习得和加工的理解至关重要。这个项目的目的是开发和测试一个明确的认知过程的计算模型，这个模型是我们快速调整能力的基础

DESCRIPTION (provided by applicant): Understanding speech is a remarkable ability: listeners need to extract asynchronously distributed phonological features from a transient and noisy signal that unfolds at speeds not under their control. Despite the ubiquitous success of spoken language processing among the general population, 5% of first graders enter school with some type of speech sound disorder that cannot be accounted for by hearing impairment. In addition, once the language system has been successfully acquired, it is susceptible to insult from injury or stroke (accounting for 1 million adults in the U.S. with some form of aphasia). One of the biggest challenges that speech understanding has to overcome is that speakers differ in how exactly they realize the same intended sound, so that one speaker's 'peach' might by physically indistinguishable from another speaker's 'beach'. Research suggests that we overcome this challenge by rapidly adapting to speaker-specific pronunciations. A more complete understanding of the perceptual and computational capacities underlying these adaptation processes is essential to advancing understanding of both normal and deviant language acquisition and processing. The aim of the proposed project is to develop and test an explicit computational model of the cognitive processes that underlie our ability to rapidly adjust to speaker-specific pronunciations ('accents'). To this end, we investigate how listeners integrate information about speakers' accents while listening to their speech. We propose that listeners weigh previous experience with other speakers against the percepts received from the current speaker. We investigate adaptation to a single speaker, adaptation to multiple speakers, and generalization from previously encountered speakers to novel speakers. The computational framework we pursue, also predicts that alternative reasons for unexpected pronunciations (such as chewing on a piece of gum), if present, can block adaptation effects. We investigate and model such 'explaining away' of unusual pronunciations. To collect large amounts of adaptation data in a fraction of the time previously required for experiments on speech perception, we have developed a web-based experimental interface that allows us to reach hundreds of thousands of participants.