*3.1.1 Respondent demographics*

We recruited 12 orchestra conductors and 12 music improvisers from our respective networks by email to fill out a survey on an unpaid, volunteer basis. These 24 professional respondents included 20 males and four females living in seven countries (Australia, Canada, France, Germany, Netherlands, Switzerland, the UK, and the USA). They had at least 5 years on the job, except for one who reported having between one and 5 years on the job. More than half (15 out of 24)

<sup>5</sup> https://mupact.com/seminar-program-may-jul-2020/aesthetic-manifestos-and-binaural-integrationan-investigation-of-pre-in-session-and-post-production-techniques-employed-in-gogo-penguinsself-titled-2020-album-release/

were touring internationally; the other nine were primarily working in France. All 24 respondents had experienced headphone monitoring while performing. Half of the conductors primarily performed for studio recording sessions with acoustically isolated instruments and/or the need to overdub on previous recordings; five for live concerts of film-scoring or new music compositions with electronic components; and one for both kinds of performance situations. Nine of the improviser respondents reported wearing headphones for more than half of their studio recording sessions; and three of them for 30% or less. Improvisers played a variety of instruments and included a singer; an acoustic bassist; a trombonist; a hornist; two saxophonists; one flutist and electronic artist; one multi-instrumentalist who played sousaphone, saxophone, clarinet, and flute; two drummers (one also conducted ensembles); and two pianists (one also played electronic keyboards and produced recordings, the other one also sang and played prepared piano). About musical genres, improvisers primarily performed jazz and/or world music (53%); pop-rock subgenres including French *variété* (27%); experimental, improvised, or contemporary music (9%).
