I had an adjustment yesterday to my Ambra MicroPs. My Audiologist noticed the compression ratio was very high–2.2 to 2.8–in most programs. During the first couple months with my Ambras, I had not noticed the “hiss burst.” The compression settings then were all less than 2.0. It frustrated him that he was unable to reduce the ratio manually. We called Phonak and the tech rep was not aware of this problem and couldn’t help us with changing the compression settings. She did say an update to Target will be out shortly and one of the new features will be the ability to manually adjust the compression ratio.
We played with the software, experimenting with different settings, and discovered if we selected “Non-linear” instead of “Linear” on one of the setup pages, we were able to partially reduce the compression ratio. This reduced the “hiss burst” by about half and it no longer trails a spoken word. It is still noticeable while someone is speaking in a noisy environment, but not to the extent as before.
A complete reset back to the Target settings does not necessarily resolve this issue. There has been only one firmware update and that does not solve the problem. Reducing SoundRecover does not appear to help the problem, but I was unable to determine that for sure. It appears to me the compression ratio is a factor of the setup selections, but there is more to this than we currently know.
With the current settings, the “hiss burst” is not a problem. The Phonak trainer will be coming to my audiologist within a month or two and I will meet with her for another adjustment.