I have a theory on TTTS that I would like to add,not that it's a fact but kinda makes sense if you think about it.
We know the Tensor muscle contracts hard from high volumes of sound in a healthy individual,let's say a noise blast of 120db causes it to contract in healthy ears then what would cause it to contract in damaged ears?
The muscle is the brains way of protecting itself and the hearing from dangerous stimuli but if it's already been damaged maybe that threshold is now a lot lower,80db or 60db of noise is now considered damaging and the brain reacts by triggering the muscles to protect itself and the cochlea or auditory nerve.The ear can't handle 120db anymore but it can handle let's say 85db at certain frequencies,once you go over that threshold the muscle contracts to protect from further damaging an already damaged hearing system.
That's my theory on it,also a symptom of nerve damage is muscle spasms which would explain the flutters people experience here.