Reports on projects which have involved U3AC members as volunteer subjects

Obviously if U3AC members have given their time as collaborators in research projects, or as subjects in experiments, they will wish to know what has eventually emerged from the research in which they took part. If the project is incomplete, some sort of interim report would be very welcome. The links below lead to short reports on some of these projects:

Note: All reports are the responsibility of the authors; its contents and any opinions expressed are not formally endorsed by the University of the Third Age in Cambridge.

Studies at the Hearing Lab, Department of Experimental Psychology
Institute of Criminology Eyewitness Memory Study
Hearing study

Studies at the Hearing Lab, Department of Experimental Psychology

In 2005, I (then a fresh post-doctoral researcher in Prof. Brian Moore’s Hearing Lab in the Department of Experimental Psychology of the University of Cambridge) first made contact with the Cambridge U3A in search of volunteers for one of my hearing studies. This study investigated the effect of hearing impairment on a series of listening tasks in a group of listeners diagnosed with sensori-neural hearing loss. However, most of these listeners were “elderly”, hence any observed poorer-than-normal performance could have been due either to the participants’ hearing loss, their age, or both. Hence, an advertisement was placed in the U3AC’s newsletter to recruit listeners aged 60 years and above with normal hearing to act as control listeners in my study. The response was overwhelming: several dozens of U3AC members replied and, consequently, were invited to visit the Hearing Lab for an initial short screening test (called the audiogram) to establish their having normal hearing sensitivity.
Since, as we grow older, our hearing gets “naturally” less acute, (a phenomenon observed mainly at the high frequencies and called presbyacusis), it was not surprising that only some of these volunteers still had normal hearing across the entire frequency spectrum. Nevertheless, I was able to find about 20 of these “rare pearls”, and amazingly all agreed to participate in a long-term, multi-session study entitled Effect of aging on auditory temporal processing. The aim of this study (funded by the Royal National Institute for Deaf People) is to address the following two questions: (i) Does age alone affect the processing of certain types of speech information?; and (ii) Is speech intelligibility dependent on cognitive factors such as attention? The study is still work in progress but preliminary results were recently presented at the International Hearing Aid Research Conference in California, USA.
Some of those volunteers whose audiograms indicated slightly less-than-normal hearing sensitivity agreed to take part in a series of laboratory experiments investigating the effect of amplification of high frequencies on the perceived quality of sounds. In recent years, several hearing-aid manufacturers have commercialized aids that are capable of amplifying sounds over a wider frequency range, i.e., they amplify more of the higher frequencies. However, relatively little is known about the actual benefits these aids might provide to listeners with mild to moderate hearing loss. Hence, in one experiment, 15 listeners (mainly composed of members of the Cambridge U3A) were asked to listen over headphones to different excerpts of music (Jazz, classic music and percussion) and speech, which had previously been processed through a hearing aid that either amplified or did not amplify the high frequencies present in the excerpts. The listeners’ task was to rate their preference for sound quality in terms of pleasantness (of the music and speech) and clarity (of the speech only). In a second experiment, participants again listened over headphones to sentences produced by a target talker in the presence of a second, interfering talker. This time, their task was to identify as many words of the target speech as possible. Taken together, these two experiments showed small but reliable effects of high-frequency amplification, but these average results hid substantial individual differences. Further research is necessary to understand why some hearing-impaired listeners, but not others, benefited from this type of amplification.
Finally, some members of the Cambridge U3A agreed to try out high-frequency hearing aids in their everyday life. To that end, each participant was individually fitted with a pair of experimental hearing aids, one in each ear, and then asked to wear the aids as much as possible during several weeks, as well as to fill in questionnaires and to keep a diary regarding their experience with the aids.
The results of these experiments are published as scientific papers in international peer-reviewed journals (see below), and a copy can be requested from Christian Füllgrabe at cf277@cam.ac.uk.

I would like to take this opportunity to express my gratitude to all members of the Cambridge U3A who have been involved in my research projects over the past years. Many volunteers have become regular “fixtures” at the Hearing Lab, thereby continuing to contribute actively to hearing science. Many thanks for your help and dedication!

Christian Füllgrabe, MRC - Institute of Hearing Research, Nottingham
October 2010

Published research involving members of the Cambridge U3A as study participants:
Moore, B.C.J., Füllgrabe, C., & Stone, M.A. (2010). Effect of spatial separation, extended bandwidth, and compression speed on intelligibility in a competing-speech task. Journal of the Acoustical Society of America, 128, 360-371.

Füllgrabe, C., Baer, T., Stone, M.A., & Moore, B.C.J. (2010). Preliminary evaluation of a method for fitting hearing aids with extended bandwidth. International Journal of Audiology, 49, 741-753.

Moore, B.C.J., & Füllgrabe, C. (2010). Evaluation of the CAMEQ2-HF method for fitting hearing aids with multichannel amplitude compression. Ear & Hearing, 31, 657-666.

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Institute of Criminology Eyewitness Memory Study
The Institute of Criminology’s research study on the effect of time of day on people’s eyewitness memory has now concluded. Many of the participants were members of U3AC, so we would like to say thank you and report back on our results.
In total 48 men and women aged 60 or older and 48 men and women aged 30 or younger took part in this research. They were first tested to see if they were morning or evening types, i.e. if they were more alert in the morning or the evening. Then they watched a brief film about a staged crime, told us what they remembered and answered questions about it. This session was scheduled either in the morning or in the evening. This meant that we had four groups: morning people tested in the morning, evening people tested in the evening (the optimally tested group), and morning people tested in the evening, and evening people tested in the morning (the non-optimally tested group).
The results were twofold: We found that when asked to give their own account of what happened in the film without being prompted by questions, people tested at their optimal time were only a tiny bit better than those tested non-optimally.
However, when we asked questions, people in the optimal testing group remembered 20 more correct details than the non-optimally tested group, and this translate into 19% more correct details of the total remembered. And crucially, while remembering more, they did not make also more mistakes. This means that taking time of day into account when interviewing witnesses could help to improve witness statements.
We also found some age differences between young and old participants but they were quite surprising. Only when asked questions the younger group remembered more correct details than the older group. When asked to tell everything they could remember without prompts, the older group remembered more! We believe the reason for this was that the older group took the test very seriously and was very motivated to perform well, while the students seemed to be perhaps more motivated by the money we paid for participation than by wanting to do well in the test.
Nevertheless, this is one of the rare findings where an older group performs better in a memory tests than a younger group. In witness situations it is often the initial report provided by the witness that is important, which would be equivalent to the unprompted report in our study. Thus our results show that, when motivated to do well, older witnesses can report as much as young ones, sometimes even more.
For us at the Institute of Criminology, this has been a very valuable study which has contributed much to our understanding of eyewitness memory. I would like to thank all those who have taken part!
Dr. Katrin Mueller-Johnson, Institute of Criminology, University of Cambridge, < kum20@cam.ac.uk >

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Hearing study
Some of you will remember coming to the Linguistics Department at Cambridge University last year to participate in a hearing study. In the course of the testing session, I first measured your ability to hear tones of different frequencies, and then asked you to listen to sentences and write down what you heard. With the help of those sentences I measured how well you could understand target words that contained an “r” depending on whether or not the first half of the sentence contained acoustic cues congruent with an upcoming “r”. The results are now in and I thought you might like a quick summary of the results. I did indeed find that the subtle cues in the first half of the sentence made it easier for listeners to later perceive the “r”-word. Moreover, these same cues made it less likely for listeners to correctly hear “non-r” target words when they were present but not followed by a word with the letter “r”. This result pattern was particularly true for listeners with very good hearing in high frequencies. As high-frequency hearing worsened, listeners were less likely to hear those subtle “r” cues, and having them in the beginning of the sentence did neither help nor hinder word perception. Much to our fascination, listeners with hearing loss in the high frequencies started to use other information to aid perception, particularly information on word frequency. Hence, when in doubt of the correct word, they would choose that word, which is most common to the English language. These results are interesting because they show not only that listeners change their listening strategies to accommodate changes in hearing, but also how listening strategies can be adjusted. Moreover, we would like to argue that having to rely on knowledge (of word frequency for instance) rather than the acoustic information inherent in the signal (signified by our subtle manipulation at the beginning of each sentence) is more effortful and tiring over the course of a long conversation, and that this might be one of the reasons why listening in noise becomes more exhausting as we age. Many thanks to everyone who agreed to participate in the study!

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