Auditory and auditory-visual Lombard speech perception by younger and older adults

The current study examined older and younger adults' perception of auditory and auditory-visual Lombard speech. A staircase procedure was used to estimate the SNR required for participants to achieve 50% correct auditory identification of Quiet and Lombard speech (CVC and VCV stimuli). Stimuli were then presented in auditory only (AO), visual only (VO) and auditory visual (AV) conditions in a speech identification task in noise using the SNR set in the staircase procedure. Results showed that both groups received comparable benefit from the auditory Lombard speech modifications. Both age groups received significant benefit from the AV Lombard speech with the degree of AV Lombard benefit greater for the older adults on the CVC stimuli. In contrast, for the VO condition, older adults' overall perception was relatively poor. Although Lombard speech improved their lip-reading ability on the CVC stimuli, they received no benefit on the VCV stimuli. The findings suggest that although lip-reading abilities may diminish with age, older adults can still receive substantial benefit from the integration of the auditory and visual Lombard speech in AV speech perception.