What happens to an acoustic signal after it enters the mind of a listener? Previous work has demonstrated that listeners maintain intermediate representations over time. However, the internal structure of such representations—be they the acoustic-phonetic signal or more general information about the probability of possible categories—remains underspecified. We present two experiments using a novel speaker-adaptation paradigm aimed at uncovering the format of speech representations. We exposed adult listeners (N = 297) to a speaker whose utterances contained acoustically ambiguous information concerning phones (and thus words), and we manipulated the temporal availability of disambiguating cues via visually presented text (presented before or after each utterance). Results from a traditional phoneme-categorization task showed that listeners adapted to a modified acoustic distribution when disambiguating text was provided before but not after the audio. These results support the position that speech representations consist of activation over categories and are inconsistent with direct maintenance of the acoustic-phonetic signal.

声音信号进入听众的脑海后会发生什么？以前的工作表明，听众会随着时间的推移保持中间表示。然而，这种表示的内部结构——无论是声学-语音信号还是关于可能类别概率的更一般信息——仍未明确。我们提出了两个使用新的说话人适应范式的实验，旨在揭示语音表示的格式。我们暴露了成年听众（N= 297) 给一个说话者，该说话者的话语包含有关音素（以及单词）的声学模糊信息，我们通过视觉呈现的文本（在每次话语之前或之后呈现）来操纵消歧线索的时间可用性。传统音素分类任务的结果表明，当在音频之前而不是之后提供消歧文本时，听众会适应修改后的声学分布。这些结果支持语音表示由类别激活组成的立场，并且与声学语音信号的直接维护不一致。