Personal Sound Amplifiers for Adults Seniors, Rechargeable Amplifiers Devices with Earbuds Voice Enhancer Noise Cancelling 1 pair

To get rid of the whistling, please follow our instructions about the insertion and adjustment: Set the volume at the lowest level. Choose the most comfortable ear dome for your ear. Make sure there is no air go through your ear canal. Wear the amplifiers before turning on the device. Adjust the volume according to the environment until you can hear clearly. Clear Sound Quality Easy To Use For Senior Portable Charging Case One Day Once Charge Is All You Need