I recently had the send my Bolero Marvel M90R aids out to have the rechargeable batteries replaced. When they were returned to me, instead of the cone shaped open domes they were now fitted with domes that looked like perforated disks. I fired up my Target software, did new feedback tests, and tried them for a day. The results were not very good.
I found out that the disk shaped domes are Phonak version 4.0, and the feedback threshold as observed on my computer screen was noticeably lower than the cone shaped domes. The result was increased sound bypassing my hearing aids, making noise reduction less effective, and more feedback if something brushed against my ears.
I went back to the original design slim tubes and cone shaped domes, and did another feedback test. Everything sounds great again!
If you use , feedback and increased ambient sound shouldn’t be an issue, and the 4.0 series domes will probably be fine. One positive regarding the 4.0 Domes is they don’t tend to fold over when removing them from your ears. Anyway I hope my experience will help others.
You’re ignoring this member’s posts.