Covert variations of a musician's loudness during collective improvisation capture other musicians' attention and impact their interactions.

While research on auditory attention in complex acoustical environment is a thriving field, experimental studies thus far have typically treated participants as passive listeners. The present study-which combined real-time covert loudness manipulations and online probe detection-investigates for the first time to our knowledge, the effects of acoustic salience on auditory attention during live interactions, using musical improvisation as an experimental paradigm. We found that musicians were more likely to pay attention to a given co-performer when this performer was made sounding louder or softer; that such salient effect was not owing to the local variations introduced by our manipulations but rather likely to be driven by the more long-term context; and that improvisers tended to be more strongly and more stably coupled when a musician was made more salient. Our results thus demonstrate that a meaningful change of the acoustical context not only captured attention but also impacted the ongoing musical interaction itself, highlighting the tight relationship between attentional selection and interaction in such social scenarios and opening novel perspectives to address whether similar processes are at play in human linguistic interactions.