1. Host (1) earplugs (4) battery (2) brush (1) earplugs cleaning rod (1)
plastic gift box (1) English Manual
2. Maximum sound output: 110±5 dB
3. Sound gain: ≥ 30 dB
4. Total harmonic distortion: ≤ 10%
5. Frequency range: 300 - 4000Hz
6. Input noise: ≤ 40 dB
7. Operating voltage: 1.5V(AG3 button battery)
8. Work Current: 4mA

1. How to wear listening AIDS?
For the first time, you may feel that your voice is not real and clear enough. Because you have become accustomed to the original hearing condition, when you use the hearing aid, you hear some unfamiliar sounds, so you cannot adapt to it for a while. The main way to solve the problem is to carry out the necessary adaptive training. Don't wear it too long at the beginning, don't use too much volume, and adapt slowly.

2. How to conduct adaptive training?
Adaptive Training of hearing aids is not complicated. The general principle is to insist on wearing and step-by-step adaptation:
(1) in terms of daily wearing time, it should be from short to long;
(2) from the perspective of volume adjustment, it should be small first and then large;
(3) from the communication environment, it is appropriate to be quiet first, then Cao Miscellaneous, first simple and then complex.
Only in such a step-by-step manner can you get through the adaptation period as soon as possible and maximize the role of listening assistance.

3. Why does hearing aid produce howling?
The earplugs and meatus acusticus contact parts are not tightly closed, and the amplified sound leaks out from the gap and returns to the microphone to be amplified again, which will produce howling. This phenomenon is similar to our common microphone whistling when approaching the stereo.
(1) the hand or an object is close to the hearing aid, because part of the sound is reflected on the palm or object and sent back to the microphone for further amplification.
(2) the hearing aid is not completely inserted into the meatus acusticus or is not tightly sealed with the meatus acusticus Wall. The amplified sound leaks and is transmitted back to the microphone.
(3) There are a lot of earwax in the ear, and ear wax embolism occurs. The amplified sound is reflected to the earwax and transmitted to the microphone again, which will also generate feedback.

4. How to avoid howling?
(1) first adjust the hearing aid machine volume adjustment knob to the position of "1", then insert the earplugs into the ear and try to tighten them, then adjust the volume to the clearest position.
(2) If the earplugs can't be plugged tightly, please try another more suitable earplugs, plug the ears tightly, and do not leak air.