I took my hearing aid into my "old' hearing aid specialist 4 times to get the whistle out and each time I didin't make it home before they started whistling again. Since I've seen you it's been 3 weeks with no whistle. How were you able to do it right the first time?
There is a 3 part answer:
1. I was trained by the best.
2. Attention to detail.
3. You had a bad fit, they were loose, and sound was leaking out causing them to whistle. Once we tightened them up, the feedback went away and now you can hear better.