Speech communication in older adults: an acoustic and perceptual investigation

由于与年龄相关的听力丧失（65岁以上常见）、与年龄相关的发音和发音质量下降，以及短期记忆和处理速度下降等认知问题的综合影响，老年人的言语交流可能很困难。过去关于老年人如何感知和产生语音的研究倾向于使用受控材料（如阅读单词或句子）独立地考虑这些能力。这些研究几乎没有告诉我们，老年说话者在使用语言进行交流时是如何发挥作用的，以及这些不同因素是如何相互作用的。例如，有研究表明，老年人从看到对话者的对话中获益，但视听讲话比听觉讲话对认知过程的要求更高，这会导致听者付出更多努力，减少信息回忆。在我们的项目中，我们建议全面了解老年人在与他人交流的情况下的语言产生和感知。与年龄相关的听力损失的成年人和听力正常的老年人的罕见组将被包括在内，以及年轻的成年人对照组。在研究1中，与另一个说话者的交流，在阅读句子或完成解决问题的任务时，要么是在良好的听力条件下，两个说话者都能正常听到对方的声音，要么是在不利的条件下，参与者必须把他们的信息传达给另一个模拟听力损失的说话者，或者是在嘈杂的背景下说话。这些比较将使我们了解老年人能够调整他们的语言以克服听力困难的程度，这是一项在日常生活中语言交流中至关重要的技能。我们将获得参与者讲话的高质量数字录音，但也将通过放置在脖子上的传感器，记录他们声带振动的信息，这决定了他们的声音质量。视频记录也将被分析，以调查老年说话者是否会像年轻说话者一样，使用眼神凝视和头部手势来表示话语的某些方面，如转向和反向传递（例如，说“好的”来表示理解）。在研究2中，听力正常和受损的老年和年轻听众将在良好和不利的听力条件下观看研究1中记录的一些句子材料。测试将在单独的听觉和视听条件下进行。可理解性测试将进行，以了解年龄、听力状况和视觉线索对语言理解的影响，并了解老年人为抵消不良沟通条件的影响而做出的“清晰语言”调整是否能给年轻人带来同样的好处。句子回忆测试也将进行，以调查听“清晰的语言”是否减少了听力的努力。这个项目将使人们更好地了解衰老对语言交流的影响，以及在“健康老年人”人群中可能导致语言交流退化的各种因素。这些基准将对从事与有健康并发症的老年人沟通方面工作的言语和语言治疗师以及听力学家等从业人员有所帮助。更好地了解老年人所遇到的沟通困难及其克服这些困难的策略，也将有助于社会工作者和致力于改善老年人生活质量的护理专业人员等专业人员，以及远程医疗和远程监测语音技术设备的开发人员。重要的是，这项研究也将有助于我们对整个生命周期的语言感知和生产发展的基本理解。

Speech communication can be difficult for older people, due to the combined effects of age-related hearing loss, which is common over the age of 65, age-related decline in the quality of phonation and speech articulation, and cognitive problems such as poorer short-term memory and processing speed. Past studies of how older individuals perceive and produce speech sounds have tended to consider these abilities independently of each other using controlled materials, such as read words or sentences. These studies tell us little about how older speakers function when using speech for communicative purposes, and how these various factors interact. For example, it has been shown that older people benefit from seeing their interlocutor in conversations, but audiovisual speech places greater demands on cognitive processing than auditory speech which leads to increased listener effort and reduced information recall. In our project, we propose to gain a comprehensive account of older people's speech production and perception in situations involving communication with another individual. Adults with age-related hearing loss and the rarer group of older adults with normal hearing will be included as well as younger adult controls. In Study 1, communication with another speaker, while reading sentences or completing a problem-solving task, will either be in good listening conditions, where both speakers hear each other normally, or in adverse conditions, where the participant has to get their message across to another speaker who has a simulated hearing loss or when both are speaking in a noisy background. These comparisons will enable us to get a sense of the degree to which an older person is able to adapt their speech to overcome difficult listening conditions, a skill which is of paramount importance in speech communication in everyday life. We will obtain high-quality digital recordings of the participants' speech but will also, via sensors placed on the neck, record information about their vocal fold vibration, which determines the quality of their voice. Video recordings will also be analysed to investigate whether older speakers make use of eye gaze and head gestures to signal aspects of discourse such as turn-taking and back-channelling (e.g., saying 'okay' to signal understanding), to the same degree as younger speakers. In Study 2, older and younger listeners with normal and impaired hearing will be presented some of the sentence materials recorded in Study 1 by all speaker groups in good and adverse listening conditions. Tests will be presented in both auditory-alone and audiovisual conditions. Intelligibility tests will be run to see what impact age, hearing status and visual cues have on speech understanding and to see whether the 'clear speech' adaptations made by older speakers to counter the effects of poor communication conditions gives the same benefit to that of younger speakers. Sentence recall tests will also be run to investigate whether the listening effort is reduced listening to 'clear speech'. This project will lead to a better understanding of the effects of ageing on speech communication and of the various contributing factors to potentially degraded speech communication in a population of 'healthy aged' individuals. These benchmarks will be of use for practitioners such as speech and language therapists and audiologists who work on aspects of communication with older people who have health complications. A better understanding of communication difficulties that older individuals experience and of their strategies to overcome these difficulties will also assist professionals such as social workers and care professionals who work to improve quality of life for older people, as well as developers of speech technology devices for telemedicine and remote monitoring. Importantly, this research will also contribute to our basic understanding of speech perception and production development across the lifespan.