If the earmuffs are not fully inserted into the ear canal or air leaks from the earmuffs, it will cause an annoying whistle. Causes of whistling/noise: In order to make a small hearing aid, the internal amplifier and microphone are placed close to each other.
eBay
【HEARING AIDS】-Different from traditional head-mounted and ear-hook hearing aid,Our hearing amplifier is very small and lightweight,Nearly invisible that is convenient for you to attend various occasions.
eBay
The cause of howling/noise: To make a small size hearing aid, the internal amplifier and the microphone are close to each other. The sound is continuously received and extended, so it has a certain possibility of producing howling after power-on.
eBay
If the earmuffs are not fully inserted into the ear canal, or if the air leaks out of the earmuffs, it will cause an annoying whistling sound. -Specially designed for hearing-impaired people, more suitable for the ear canal.
eBay
Style: Behind the Ear (BTE). 1 x Behind-the-ear hearing aid (single). 1 x Instruction manual. 【Easy to use】The simple and user-friendly design is suitable for elderly people, so that they can communicate more conveniently and efficiently and improve their quality of life.
eBay
Features:-It adopts a lightweight in-ear design and comes with earplugs of different sizes to ensure a tight fit, comfortable wearing and reduced howling.-The left ear is blue and the right ear is red, making it easy to tell which ear it applies to. With obvious on/off button for easy operation.-Hidden design, looks like a Bluetooth headset, so you won't feel uncomfortable.-Equipped with a 300mAh large-capacity charging box, it can be fully charged in about 30 minutes and can be used for about 6 hours. The charging box can provide 5 charges when fully charged.-Built-in intelligent digital chip, intelligent noise reduction, no fear of noisy environment, providing excellent sound quality.Specification:Maximum sound output: 118+/- 3dBSound gain: >= 35dB+.
eBay
1 Pair Mini Invisible Hearing Aids In-Ear Digital Enhancer Voice Sound Amplifier 300mAh with Charging Case. 【SMALLER AND CONVENIENT DEVICE】Upgraded design, 20% smaller than other similar products, and it has a miniature appearance comparable to headphones, so you won't attract any unpleasant glances when using it.
eBay
● Lightweight and small: The machine itself is ultra-low background noise and small lightweight body (ITE in the ear design), very comfortable to wear on left / right ear. ● Digital sound amplifier: Advanced digital signal processing technology provides a high quality of natural sound, detects and identifies sound waves and changes the amplification of the channel in which the noise is located to make normal speed clearer.
eBay