The effects of informational and energetic/modulation masking on the efficiency and ease of speech communication across the lifespan

Children and older adults have greater difficulty understanding speech when there are other voices in the background (informational masking, IM) than when the interference is a steady-state noise with a similar spectral profile but is not speech (due to modulation and energetic masking; EM/MM). We evaluated whether this IM vs. EM/MM difference for certain age ranges was found for broader measures of communication efficiency and ease in 114 participants aged between 8 and 80. Participants carried out interactive diapix problem-solving tasks in age-band- and sex-matched pairs, in quiet and with different maskers in the background affecting both participants. Three measures were taken: (a) task transaction time (communication efficiency), (b) performance on a secondary auditory task simultaneously carried out during diapix, and (c) post-test subjective ratings of effort, concentration, difficulty and noisiness (communication ease). Although participants did not take longer to complete the task when in challenging conditions, effects of IM vs. EM/MM were clearly seen on the other measures. Relative to the EM/MM and quiet conditions, participants in IM conditions were less able to attend to the secondary task and reported greater effects of the masker type on their perceived degree of effort, concentration, difficulty and noisiness. However, we found no evidence of decreased communication efficiency and ease in IM relative to EM/MM for children and older adults in any of our measures. The clearest effects of age were observed in transaction time and secondary task measures. Overall, communication efficiency gradually improved between the ages 8–18 years and performance on the secondary task improved over younger ages (until 30 years) and gradually decreased after 50 years of age. Finally, we also found an impact of communicative role on performance. In adults, the participant asked to take the lead in the task and who spoke the most, performed worse on the secondary task than the person who was mainly in a ‘listening’ role and responding to queries. These results suggest that when a broader evaluation of speech communication is carried out that more closely resembles typical communicative situations, the more acute effects of IM typically seen in populations at the extremes of the lifespan are minimised potentially due to the presence of multiple information sources, which allow the use of varying communication strategies. Such a finding is relevant for clinical evaluations of speech communication.