Older adults often have more difficulty than their younger counterparts in focusing on one speaker when other people are talking. This is especially the case when operating in their second language, an issue EU-funded research is delving into.
Age-related cognitive and/or sensory changes may explain the difficulties in communication that older listeners experience. An inability to perceptually segregate target speech, or a delay in accomplishing this, from competing sounds puts this population at a disadvantage vis à vis younger adults.
Further details: Communication difficulties for older adults in noise