The cause of howling/noise: The internal amplifier and the microphone are close to each other of the hearing aid, and the sound is continuously received and expanded, so it has a certain possibility of produce howling after power-on.
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5Pcs 401215 3.7V 90mAh Polymer Lithium Rechargeable Battery FOR 3D Glasses MP3 Toy Watch Selfie Stick Hearing Aid Reading Pen
Aliexpress UK
2 Hearing aids. fits perfectly behind the ears and even comfortable to wear with any pair of glasses. These are the simplest ready to use personal hearing amplifier devices. Using the bendable ear line to place, easy to adjust when you put it into the ear.
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Our accessories include earplugs of different sizes. This small device allows you to wear comfortably and provide a clear sound. 1 Hearing Amplifier. Maximum saturation sound pressure level (SSPL): 130dB±4dB.
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About this item .
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Insert the hearing aid into the ear canal,adjust its position in the ear canal until the soft eartip is fully deployed and fill the ear canal. Turn off the hearing aid if you don't use it. Clean the ear canal before use.
eBay
2 Hearing aids. These are the simplest ready to use personal hearing amplifier devices. Using the bendable ear line to place, easy to adjust when you put it into the ear. fits perfectly behind the ears and even comfortable to wear with any pair of glasses.
eBay
Insert the hearing aid into the ear canal,adjust its position in the ear canal until the soft eartip is fully deployed and fill the ear canal. 1 x Hearing Aids. Turn off the hearing aid if you don't use it.
eBay
2 Hearing aids. These are the simplest ready to use personal hearing amplifier devices. Using the bendable ear line to place, easy to adjust when you put it into the ear. fits perfectly behind the ears and even comfortable to wear with any pair of glasses.
eBay