V-183 Bluetooth type Hearing Aids Aid Adjustable Tone Sound Amplifier Hear Clear Enhancement Ear Health Care Deafne About Whistle , you can do this 3 steps to remove it. 1. Choose a suitable earplug to make the product sealed in the ear canal 2. Low down the sound volume 3. When you put into battery , please be quick , to put the product into the ear Note: Adjust volume to the minimum before wearing. Choose an earplug of slightly bigger size to avoid whistler. Increase volume gradually to avoid sudden increase in sound. Keep the ear plug clean Remove the battery if you don't use it for long time. Details: 100%competive price Advanced high quality analogue hearing aid Volume control ON/OFF swich Volume control Different size noise prevention earplug for selection Clear and loud voice Model:V-183 Hearing Aid Specification: Bluetooth type hearing aid: Max Sound Output: 129dB 4dB Max Sound Gain: 55dB 5dB Harmonic Wave Distortion: 5% Frequency Range: 2503800 Hz Input Noise: 30dB Battery: AG13 Working Voltage dc1.5V Working Current: 4mA Package included: 1 x hearing aid amplifier 3 x earplug (different size) 2 x AG5 button cell battery 1 x manual 1 x box