yes deaf therapist, that's me
and yes it's a therapist not a masseuse, although I doubt you'd get a hard time using the term unless the person was really anal retentive. I manage to do this but I'm not completely deaf, well without my hearings I am lol. I'm profoundly deaf but with my hearing aids I'm HoH....sorry I'm kind of murky on the labels not sure exactly where I fit. I miss more than I "hear" but I get by well enough to communicate with the hearies, but most of our communication has be done premassage.
You're going to have to do that as well. Most of the massage, if you talk to them you'll be taking to the back of their head and they might not even know you
are talking. If you need to ask them something tap them on the shoulder and get your head over by the face cradle so they don't have to break their neck to look at your face. Learning ASL isn't imperative, if that's going to be niche though it'd be a good idea. But using a few signs as far as pressure goes is imperative. I've even had clients come up with their own. After I've told them when they're face down on the table I won't understand anything they say they'll be all "oh that's okay I 'm just going to sleep anyway. I'll do this if I want more pressure *insert whatever they've come up with* or this if I want less". Thumbs up, is pretty much the best if they like the pressure, suggestions for less pressure, they can pat their hand down a couple times, more pressure? Do you know the sign for more? google it if you don't, it's really a 2 handed sign but they can use one hand for it and do it against the face cradle. Doesn't really matter what you do, it does't have to be "ASL" as long as you both know what it means.
Now music?? This is really going to depend on the person's level of loss. You are going to have a hard enough time communicating without adding background noise. Yes to you it's background music, for us, for most of us, it is gong to be background
noise, and it's going to make it harder for them to understand you. So even if they think they want it, it might not be a good idea. There is music all through my spa, luckily every room has a volume control dial and I turn it way down in my room. It drives me nuts, it's not music, it's annoying messy noise. Some other things to think about, let's say they just want to feel the vibrations......if you do that it is going to be really really really loud for
you.....so loud you might have a hard time hearing
them. Also, is this a spa setting? If so not ever body is going to want to hear your music, which is what would happen if you had it cranked enough for them to feel the bass.
Not to rain on your parade or anything. Obviously you have nothing but the best intentions and you don't really understand. That's okay I wouldn't expect you to. Music just simply isn't the same for us as it is to you and personally I think it would make it harder for you to communicate with your client which could make a potentially frustrating situation even more frustrating, for both of you. But it's really going to boil down to...just how deaf they are.