1. Full digital processing with imported chip, four channels, clear sound, less noise
2. Adaptive acoustic feedback cancellation
3. Listening modes (noraml, noise reduction, TV and outdoor modes)
4. Procedure signal sound
5. Volume memory
6. Mode memory
7. Color: silver and black, black
1. Max Sound Output: ≤125dB+3dB
2. Max Sound Gain: 45dB±5dB
3. Average Sound Gain: 35dB±5dB
4. Harmonic Wave Distortion: ≤5%
5. Frequency Range: 400Hz~5500Hz
6. Input Noise: ≤24dB
7. Battery: A13 zinc air battery
8. Rated Current: ≤3mA
9. Working Voltage: DC 1.45V