For teaching in anything but a very small room, aerobics instructors generally use a head-worn microphone:
Depending on the microphone, there is often a battery pack attached to it with a cord:
Since it’s not really feasible to hold the battery pack in your hand while dancing around a plastic platform, most instructors also use belts:
So of course, when I showed up at the gym to sub a step class the other day and realized I had lost my battery-pack belt, I panicked. The room was big enough that attempting to teach the class unamplified would have wreaked havoc on my vocal cords; furthermore, the class was pretty full, which meant the music volume had to be pretty high. The gym had no extra belts around, and class was supposed to start in a minute and a half, so I did the only thing I could think of, which was to shove the battery pack down the front of my shorts. For ten or fifteen minutes, everything was fine; the class was enthusiastic, the microphone worked well, and the battery pack stayed put.
Then it started to inch its way towards the leg opening in my shorts.
For another twenty minutes or so I taught essentially one-handed, indicating directions with my right hand and yanking on the cord with my left hand every fifteen seconds to keep the battery pack from moving any further.
Then even this stopped working. For a brief period I just held the thing in place by clutching my left shorts leg, but eventually I had to let go for some reason or another and the battery pack immediately fell out of my shorts. I actually reached into my shorts and adjusted it, but to no avail; some cruel god out for vengeance had decided that this class should think my penis was a black plastic parallelepipedon.
This happened a few times until I could stand it no longer; I told everybody to get a drink of water, went into the corner and, while pretending to change the CD (that “pause” button can be really handy), readjusted myself so that I could hold the battery pack in place with my ab muscles, and continued teaching. It was at this point that the connection between the battery pack and the microphone started to fail.
I ripped the thing off and shrieked at the top of my lungs for the rest of the class.
Afterwards, as I collected my equipment and headed for the shower, I saw that the battery pack actually had a clip on it, so I could have just stuck the thing on the back of my shorts and been done with it.
But that wouldn’t have satisfied the cruel god out for vengeance, so I suppose it’s just as well I didn’t force him to take more extreme measures.