I don't know about this noise but you might ask her doctors whether it could be stridor, a symptom of multiple system atrophy (MSA), another synucleinopathy. My wife was recently diagnosed, after a 4-year ordeal of seeking a diagnosis, as having MSA with predominant parkinsonism. In her case, early parkinsonism (shuffling, bradykinesia) plus disequilibrium and falls were a "red flag" for MSA (or should have been - her original doctors missed it) . She is now experiencing both urinary retention and incontinence as well. I understand that parkinsonism with early autonomic symptoms, like incontinence, may also be a red flag for MSA.