Sentence Recognition in the Presence of Competing Speech Messages Presented in Audiometric Booths with Reverberation Times of 0.4 and 0.6 Seconds

This study examined whether differences in reverberation time (RT) between
typical sound field test rooms used in audiology clinics have an effect on speech
recognition in multi-talker environments. Separate groups of participants listened to
target speech sentences presented simultaneously with 0-to-3 competing sentences
through four spatially-separated loudspeakers in two sound field test rooms having
RT = 0:6 sec (Site 1: N = 16) and RT = 0:4 sec (Site 2: N = 12). Speech recognition
scores (SRSs) for the Synchronized Sentence Set (S3) test and subjective estimates
of perceived task difficulty were recorded. Obtained results indicate that the change
in room RT from 0.4 to 0.6 sec did not significantly influence SRSs in quiet or in
the presence of one competing sentence. However, this small change in RT affected
SRSs when 2 and 3 competing sentences were present, resulting in mean SRSs that
were about 8–10% better in the room with RT = 0:4 sec. Perceived task difficulty
ratings increased as the complexity of the task increased, with average ratings similar
across test sites for each level of sentence competition. These results suggest that
site-specific normative data must be collected for sound field rooms if clinicians
would like to use two or more directional speech maskers during routine sound field
testing.