Doctoral Dissertation Research: Speech perception in bilingual and monolingual speakers under normal and adverse listening conditions

听者在次优听力条件下识别单词和语音的能力是对日常语言使用的一种显著适应，为了充分理解这种能力，有必要澄清先前的语言经验在形成这种能力中的作用。最近的研究表明，听者是目标语言的单语者还是双语者在形成这种能力方面起着重要作用。在Aline Godfroid博士的指导下，Jens Schmidtke先生将在他的博士论文中研究双语使用者在噪音中的语音感知（SPIN）。虽然嘈杂的环境通常会使理解语言变得更加困难，但噪音似乎给双语者带来了额外的负担。许多研究的结果表明，单语者和早期双语者在安静的条件下用他们的主导语言进行测试时表现相同；然而，双语者比单语者更容易受到不利听力条件的影响。尽管这一发现相当有力，但对于双语自旋的认知需求以及噪音如何实时影响双语语音感知，我们所知相对较少。在本研究的第一部分，研究人员将调查单语和早期双语听众中自下而上（音素感知）和自上而下（执行功能）过程的个体差异，这些过程有助于SPIN。为此，参与者将完成SPIN测试，并使用各项测试（词汇知识、工作记忆、听觉注意和音素识别能力）的结果来预测SPIN的表现。预测是，双语者将更多地依赖于自上而下的过程来弥补自下而上信息处理的不足。在研究的第二部分，研究人员将通过记录听众的眼球运动来实时调查SPIN。在视觉世界眼动追踪范式中，参与者看到屏幕上物体的图片，同时听到点击其中一张图片的指令。考虑到对图片的眼球运动与正在进行的语言处理密切相关，结果将显示噪音如何影响当下的语言感知。研究人员预测，与单语者相比，双语者更容易被声音相似的图片分散注意力，因此单词识别速度更慢。这些实验结果可以帮助我们更好地理解SPIN的双语劣势。结果也可能加深我们对听力灵敏度以外的因素如何影响双语者在噪音中听到的能力的理解，从而对广泛的研究人员和实践者有价值。

The ability of listeners to identify words and speech sounds in sub-optimal listening conditions is a remarkable adaptation to the everyday use of language, and in order to understand this capacity fully it is necessary to clarify the role of prior linguistic experience in shaping this ability. Recent research suggests that whether a listener is a monolingual or bilingual speaker of the target languages plays an important role in shaping this ability. Under the direction of Dr. Aline Godfroid, Mr. Jens Schmidtke will investigate speech perception in noise (SPIN) in bilingual speakers for his dissertation research. While noisy environments generally make understanding speech more difficult, noise seems to put an extra burden on bilingual speakers. Results from many studies suggest that monolinguals and early bilinguals tested in their dominant language perform the same under quiet conditions; however, bilinguals suffer more from adverse listening conditions than monolinguals. Though this finding is quite robust, relatively little is known about the cognitive demands of bilingual SPIN and how noise affects bilingual speech perception in real time.In the first part of this study the researchers will investigate individual differences in bottom-up (phoneme perception) and top-down (executive functions) processes that contribute to SPIN in monolingual and early bilingual listeners. To this end, participants will complete a test of SPIN and results from various tests (vocabulary knowledge, working memory, auditory attention, and phoneme discrimination ability) will be used to predict SPIN performance. The prediction is that bilingual speakers will rely more on top-down processes to compensate for weaker processing of bottom-up information. In the second part of the study, the researchers will investigate SPIN in real time by recording listeners' eye movements. In the visual-world eye-tracking paradigm, participants see pictures of objects on a screen while they hear instructions to click on one of the pictures. Given that eye movements to pictures are closely linked to ongoing language processing, results will show how noise affects speech perception in the moment. The researchers predict that, in bilinguals, noise will result in greater distraction by pictures with similar sounding referents and thus slower word recognition compared to monolinguals.Results from these experiments may help us better understand the bilingual disadvantage for SPIN. Results may also deepen our understanding of how factors other than hearing acuity contribute to bilinguals' ability to hear in noise and thus be of value to a wide range of researchers and practitioners.