Aids make hissing noise

I am 51 have a mild to moderate hearing loss and have been wearing NHS aids for 3 years. My first pair were the normal mould type and the first time I put them in I noticed a hissing noise which the audiologist dismissed saying it was he lights in the room (??). over the coming weeks I discovered that when in a quiet room the hissing was so loud that it prevented me from hearing quiet noises. I went back to the audiologist but she didnt seem to believe me. She did agree though to change my aids for the in-ear dome type. This greatly reduced the hiss but I still notice it when I am in a quiet room. Are the aids faulty? or is this quite normal with NHS aids?

It shouldn’t be the norm. It might be the adjustment need work or that the hardware has a problem. One of the English providers can probably help you further if you cite the model you are wearing.

It might be microphone noise. You can search the forums for microphone noise and find a fair amount of discussion.

Could be circuit noise or moisture getting into the HA’s from rain or sweat.

Hi seb. It’s definitely not moisture. As I said the hissing was there from the start when I was fitted with them in the hospital.
I think MDB has a point though. having read other threads about microphone noise it may be that. So I guess I just have to deal with it. I don’t notice it at work where its noisy and I just take them out when I get home and its quiet. Annoying though

Beside the mic noise, it can also be the static floor noise of the amplifier itself, although for digital HAs, the signal to noise ratio should have been high enough that you shouldn’t hear the floor noise that easily.

Or maybe there’s some kind of signal processing going on like compression or expansion in one of the settings that inadvertently raises the floor noise. Like maybe there’s a soft sound enhancement feature that’s turned on and the side effect of amplifying the soft sound is also amplifying the floor noise with it. I’m not saying that it’s the case for your HA, but it’s just an example of the kind of thing to be looking for.

I do hear some floor noise in my Oticon OPN when I go to the directional noise reduction program mode. Nobody could explain to me why. Fortunately I don’t need to use that mode often at all so I just removed that program from my setting.

but whatever is causing it I don’t see I can do anything about it if the audiologist doesn’t even believe its there :frowning:

Your audiologist should turn the gain of the very soft sound down. I had this myself with my NHS aids.

Your audiologist can listen to the aids with a special scope and should be able to hear the floor noise if it is present at the time of your visit. You could also ask the audiologist if you qualify for a different set of aids. Some brands are worse for floor noise and it depends on your hearing and whether it is preserved in the frequencies where the floor noise is occurring. I had to switch from Resound aids due to floor noise which was almost certainly microphone noise when the aids were using all the microphones. If your audiologist won’t believe you ask for her supervisor or someone more experienced.