Age-related benefits in dip-listening for engaging spoken stories
Many adults in their 50s and 60s have difficulty understanding speech in the presence of background sound, such as in crowded restaurant. Fluctuations in the intensity of background sound can help a listener to comprehend speech because the listener can perceive ‘glimpses’ of the speech when the intensity of background sound is low. We call this ‘dip listening’ or ‘speech glimpsing’. Most previous research suggests older adults do not benefit as much as younger adults from speech glimpses for comprehension, but this work has used relatively boring disconnected sentences that do not mirror speech in everyday life.
We investigated whether older adults would benefit from speech glimpses when they listen to more naturalistic speech, such as spoken stories. Younger and older adults listened to speech in background noise. Speech stimuli were either engaging spoken stories or disconnected sentences lacking a topical thread. The background noise either fluctuated in intensity (‘speech glimpsing’) or did not fluctuate (‘no glimpsing’). The presentation of speech and background sound discontinued from time to time and listeners reported exactly the words they understood. We calculated the proportion of words they correctly understood.
Figure: Difference in intelligibility for speech masked a fluctuating vs non-fluctuating background sound
Older adults benefited less than younger adults from fluctuations in the intensity of background masking sound for the comprehension of disconnected sentences (the two leftmost bars in the figure). In contrast, older adults benefited as much as younger adults did from fluctuations in the background sound when speech was presented as an engaging spoken story (the two rightmost bars in the figure). Our study suggests that under listening situations that mirror everyday life, older adults use the speech glimpses that are occasionally released by fluctuations in background sound to comprehend speech as much as younger adults do.
Future research will investigate why older adults benefit less from speech glimpses for disconnected sentences than naturalistic spoken stories, whereas younger adults benefit similarly for both. Future research may also focus on the brain mechanisms that underlie the greater benefit from speech glimpses for spoken stories in older adults.
Vanessa C. Irsik
Ingrid S. Johnsrude
Under naturalistic listening conditions, older adults benefit equally or more than younger adults from speech glimpses that are released when background masking sound fluctuates in intensity.