I use Ear Gear on my aids. For the first three years, they were send back every 3 months due to sweat. With the ear gear, I have not sent them back in 6 years. I found the ear gear cuts out wind noise and short hair noise. Would not use aids without them. Looking at new aids, and will be putting the gear on them. I also run them through a dryer every once in a while. The gear do not change the sound in the aids.
Only drawback is the gear get sweat smells that my dog likes, so have to keep them out of her reach.