Les Mills BODYSTEP® 84 (footage from Ultimate Super Workshop Sydney, 2011) 

I have been lifting weights at gyms for many years....Why do gyms still use PA speakers in there aerobics classes. I spoke to the owner of a gym in New Zealand, and they told me the problems these loud annoying PA speakers systems cause, and the damage to peoples hearing. Why not use ceiling speakers....lots of them up in the ceiling, facing down to the ground. More smaller, less powerful, ceiling speakers....then you don't get microphone feed back... less brutal hearing damaging sound...and those big ugly heavy PA speakers that take up a lot of space, and can fall on someone if there is an earthquake. Bose and hundreds of other brands make ceiling speakers. And by having lots of smaller better quality sounding speakers, you could play aerobics music in surround sound dolby atmos etc. Those commercial surround speakers that they have in public movie cinemas would be perfect, because they have less brutal sound, and are designed for surround sound. Another good type of speaker to use is those karaoke speakers, which have good quality less brutal sound. Exercising at the gym should be relaxing, stress relief, therapeutic....not being blasted with loud PA speakers like a night club and ending up half deaf and even more stressed. It's like those loud annoying diesel buses.....apposed to the silent electric buses...I prefer the electric bus experience.