For me its headphones unless I like what is playing in the shop (we have speakers in FAI connected to the shop speakers with our own volume control. I like hard rock/metal (Disturbed, Korn, Volbeat, Slipknot, ect...)
Crazy cool stuff. Good variety. Apparently all of the guys are highly educated, classically trained musicians. Not too surprising when you listen to the music instead of just being baffled by the foreign words and throat singing. Talented group.