Team Grant-Joint call for Res Appl (JCRA) Ageing Res-ERA-AGE2 (2012-2015)
Hearing, Remembering, and Living Well: Paying Attention to Challenges that Older Adults Face in Noisy Environments
It has become increasingly clear that the difficulties that older adults have in understanding what people are saying limit their access to public spaces and interfere with their ability to socialize. Clearly, the inability of older adults to understand what is being said in the noisy situations of everyday life limits their activities, and often results in loss of standing in the family and community. As a result of the "greying" of the population, governments, non-government organizations, and seniors themselves are becoming increasingly aware of the issue, and, as a result, there is a buildup of pressure to take steps to make public spaces "hearing accessible" to older adults, and to help them overcome or compensate for their hearing difficulties. The purpose of this grant is to conduct the research that will permit these interested groups to take steps to remedy this situation based on scientifically collected evidence. Specifically, the goals of this research are to: 1) identify the situations in which older adults experience communication difficulties; 2) develop means of determining, on an individual basis, the nature of any hearing or attentional problems contributing to these difficulties; 3) develop assistive hearing devices and training strategies that will help older adults cope with these communication problems; and 4) develop a set of recommendations as to how public gathering spaces can be made more "hearing accessible" to older adults.
Operating Grant (1999-2014)
Effects of auditory and cognitive deficits on speech understanding in the elderly
Older adults often find it difficult to understand speech in everyday listening situations. These difficulties could reflect age-related deterioration in hearing abilities, in cognitive abilities (e.g., memory), or both. For example, when listening to a conversation, hearing declines might cause older adults to mishear individual words more often than younger adults. This, in turn, will often cause older adults to misinterpret the intended message. Alternatively, cognitive declines may make it more difficult for older adults to integrate information coming from different conversationalists, leading to misinterpretation of what was said. Our research program is designed to determine the relative contribution of these two kinds of declines to spoken language comprehension so that appropriate steps can be taken to improve language comprehension in older adults (e.g., assistive listening devices for hearing declines; medication and/or therapies for cognitive declines). To date, we have been able to show that declines in hearing abilities rather than declines in cognitive abilities are responsible for most of the comprehension difficulties experienced by healthy older adults when they are listening to sentences, lectures, or simple two-person conversations. We now plan to investigate the relative contribution of these two factors when the speech material becomes cognitively more complex (e.g., multi-talker conversations), and when listening becomes more difficult (e.g., the background contains intelligible but irrelevant speech). In addition, because real-life conversations are usually face to face, we will be studying spoken language comprehension when the listener can both hear and see the talkers so that the results of this research will generalize more readily to real-life situations.
Discovery Grants (2008-2013)
Studies in sensory information processing: sensory-cognitive interactions
Sensory systems are designed to extract information relevant to the perceiver's survival from a background that is often complex and noisy. Consider the task facing a person who is attempting to listen to a companion when they are walking together down a busy and noisy street. The companion's speech is but one component of the auditory scene. To perceive, understand, and respond to the speech signal, the listener must not only "pull out" the words and sentences from the background noise, she or he must determine their meaning, relate the information obtained to past experience and world knowledge, and then formulate an appropriate response. All this must be done while also using the visual information to guide one's path while walking so as to avoid obstacles, some of them potentially lethal. To accomplish this feat, the perceptual systems employ a number of signal-processing strategies to reduce background noise. First, the auditory system identifies and locates sources of sound and then links them to the appropriate visual object. Once the system has focussed in on one of these sources (the companion's voice) it filters out most of the high frequencies in the auditory scene, such as those produced by a streetcar or horn and suppresses information coming from irrelevant sources (other voices). It also "boosts" the gain on the companion's signal. One part of this proposal studies how the auditory system identifies and locates sound sources. Another part focusses on how the auditory system enhances one source relative to others. We also know that the ability of the auditory system to accomplish these tasks diminishes with age. A third part of this research attempts to characterize the nature of these age-related changes in hearing so that we can develop strategies and assistive devices to compensate for them.