To the many who have blasted out their eardrums once too often either by going to loud concerts or maximizing the volume on their ear buds, there’s hope. Yes, you might be somewhat deafened in old age, but you will have developed compensatory skills. Or so say researchers from Queen's University, Ontario, who presented their findings today at the Canadian Association for Neuroscience. They discovered that what you hear and understand of a conversation is influenced by what you are used to hearing. The familiar voices of your loved ones remain easy for you to understand.
Dr. Ingrid Johnsrude, professor of psychology, is studying how our brains meet the challenge of distinguishing specific voices in crowded, noisy, and distracting environments. “The listening conditions of everyday life present the auditory system with a formidable challenge — decomposing a complex waveform containing information about multiple sounds so that one source, such as a voice, can be identified, tracked, and understood,” Johnsrude and her co-authors wrote in a published study. “This ‘cocktail-party’ problem … presents a significant challenge to young, healthy listeners with normal hearing, and it is particularly problematic for hearing-impaired and older listeners….”
In her experiments, Johnsrude and her team exposed participants to degraded or clear speech in the presence or absence of distraction, while in some instances, the team used functional Magnetic Resonance Imaging (fMRI) to examine the activation of different brain regions. During each of the trials, the participants wore headphones and listened to two different sentences, spoken simultaneously by different voices. The participants were instructed to pay attention to one sentence while ignoring another distracting sentence; the “target” sentence always included a signal word, while the “masking” sentence did not. Next, the participants were asked to identify the correct color-number combination identified by the speaker in the target sentence. Throughout the trials, the target voice, the masker voice, or neither voice was that of the participant’s spouse.
What did the team of researchers discover? All the participants performed best when the target voice was that of their spouse. In particular, older listeners performed less capably than younger listeners when the target sentence was spoken by a stranger, yet they equaled others when the target voice belonged to their spouse. “This finding indicates that older listeners can exploit their familiarity with a speaker’s voice to mitigate the effects of sensory and cognitive decline,” noted Johnsrude and her co-authors.
In some reaspects, though, age makes no difference. No matter how old or young you may be, when in doubt, while drinking cocktails in a noisy room, turn to someone you love.
Source: Johnsrude IS, Mackey A, Hakyemez H, Alexander E, Trang HP, Carlyon RP. Swinging at a Cocktail Party: Voice Familiarity Aids Speech Perception in the Presence of a Competing Voice. Psychological Science. 2013.