There are so many variables there I hardly know where to start from...
So, first, hi! I'm actually a singer who just assembled my home studio and have been lurking around here for a couple of months absorbing knowledge. I felt the need to respond to this because I see too many people screwing up their voices unnecessarily for lack of info/knowledge/proper guidance.
So, here are my 5 cents...
- Laying down for a month may have actually softened up your muscles - higher notes require way more strength than the lower-middle ones. Remember, the higher the note, the higher the frequency you'll be vibrating in. Though you hardly notice the muscle tone loss for daily activities, for singing it is a big deal.
- The whole procedure, being laid down for so long and all the stiffness from the recovery may also have strained a muscle or two here or there - you sing with your whole body, if there's something amiss, the voice will not come as we want it. Talk with your physician, see if a couple of massage sessions can help.
- Talk to a fonotherapist. Get a videolaryngoscopy done and see if there was no actual physical damage to the muscle; if not, sometimes a couple of exercises for a few months will do the trick. Your fono will know what to do.
- Don't treat your voice as if nothing had happened - if needed be, make those beginner drills we all hate to do... Halftones, seconds, thirds, fourths, fifths, a halftone up each time... Sometimes a tone is already too much, so go slowly. And remember to breathe!
It also could be just psychological (oh, that scary high register....), but I hardly believe, given the circumstances...
Keep us posted =)
