This noise, which sounds like a whistle and is also known as feedback, can be the result of one or more issues. There are a few things you can do:
The ear bud may not be securely positioned within the ear canal. Try to re-adjust it, or choose a pair of ear tips that fit better. See one of these videos for details: BeHear ACCESS BeHear NOW
The volume may be too high. Try turning it down a bit.
Severe hearing loss in the high frequencies, which necessitates a high amount of amplification for these frequencies, may be responsible for the whistling. If this is the case, contact our tech support group with a screen shot of your Hearing Assessment results. They may be able to adjust some of the values to improve the situation.
If none of the above solves the problem, you may have wax build-up in your ear.