... Distortion:≤10%Frequency Range:450Hz~3000HzInput Noise:≤30 dBBattery:Rechargeable NI-MH batteryWorking VoltageDC 1.5VWorking Current:≤4mAMeasurement:22* ... serious externa, otitis media, double plane pyorrhea than are not completely atresia gas guide, can consider to use hearing the ... hearing aids from shocks, falling, humidity and high-temperatureWhen not in use, please close the hearing aid to extend ...