Relationship Between Auditory Distraction and Emotional Dimensionality for Non-Speech Sounds.

Objectives: If task-irrelevant sounds are present when someone is actively listening to speech, the irrelevant sounds can cause distraction, reducing word recognition performance and increasing listening effort. In some previous investigations into auditory distraction, the task-irrelevant stimuli were non-speech sounds (e.g., laughter, animal sounds, music), which are known to elicit a variety of emotional responses. Variations in the emotional response to a task-irrelevant sound could influence the distraction effect. The goal of this study was to examine the relationship between the arousal (exciting versus calming) or valence (positive versus negative) of task-irrelevant auditory stimuli and auditory distraction. Using non-speech sounds that have been used previously in a distraction task, we sought to determine whether stimulus characteristics of arousal or valence affected word recognition or verbal response times (which serve as a measure of behavioral listening effort). We anticipated that the perceived arousal and valence of task-irrelevant stimuli would be related to distraction from target stimuli.

Design: In an online listening task, 19 young adult listeners rated the valence and arousal of non-speech sounds, which previously served as task-irrelevant stimuli in studies of auditory distraction. Word recognition and verbal response time data from these previous studies were reanalyzed using the present data to evaluate the effect of valence or arousal stimulus category on the distraction effect in quiet and in noise. In addition, correlation analyses were conducted between ratings of valence, ratings of arousal, word recognition performance, and verbal response times.

Results: The presence of task-irrelevant stimuli affected word recognition performance. This effect was observed generally in quiet and for stimuli rated as exciting (in noise) or calming (in quiet). The presence of task-irrelevant stimuli also affected reaction times. Background noise increased verbal response times by approximately 35 msec. In addition, all task-irrelevant stimuli, regardless of valence or arousal category, increased verbal response times by more than 200 msec relative to the condition with no task-irrelevant stimuli. Valenced stimuli caused the largest distraction effect on response times; there was no difference in the distraction effect on verbal response times based on the stimulus arousal category. Correlation analyses between valence ratings and dependent variables (word recognition and reaction time) revealed that, in quiet, there was a weak, but statistically significant, relationship between valence ratings (absolute deviation from neutral) and word recognition scores; the more valenced a stimulus, the more distracting it was in terms of word recognition performance. This significant relationship between valence and word recognition was not evident when participants completed the speech task in noise. There was no relationship between stimulus ratings (arousal or valence) and reaction time in quiet or in noise.

Conclusions: Valenced (positive and negative) or exciting task-irrelevant non-speech sounds can negatively affect word recognition and increase listening effort. Future study should consider the emotional content of task-irrelevant stimuli when evaluating potential distraction effects.