We Stand Behind Our Products Please read the following troubleshooting, which will solve 99% of customes' problem Charging - For the first time to charge, please remove the little plastic sticker on the end of the device which will stop the charging, it is used to protect the device before using.Fitting - Please try all the size of domes in the accessories, then find the size which fits best. Good fitting will help to prevent from whistling or falling out.Tinnitus Mode - If you don't have tinnitus problem, please be sure that you are using mode 1 or mode 2, they will be perfect for quiet and noisy environment. Mode 3 is only for tinnitus problem, in this mode, you can hear white noise which is for tinnitus masking. When you hear the white noise, that's because you choose the Mode 3, not because the device is defective.Maintainence - Please clean the domes and dustsceen every day to be sure it's not blocked by ear wax. If the users is oil-ear, it's necessary to replace the dusctscreen and domes every 1-2 weeks. Keep the device not be blocked is essential to keep the device to work and perform perfectly.Support - Your satisfaction is our first priority. The support team will always be available in time.