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OTP-GSM89 Voice activated GSM listening device

GSM Listening device


  • Voice active monitoring, when detect voice level higher then voice setting sensitivity, the module will send SMS and making call automatically.
  • Can set 4 sensitivity voice level of the microphone for detect voice in the area.
  • Can be able turn off the voice detect function through SMS
  • The microphone sensitivity can be set through SMS
  • External sensor detect pin with hi voltage detectable
  • Can be set ON or OFF for external detect point through SMS



GSM 900/1800/1900
Power consumption
20mA standby mode
200mA monitoring mode
Audio Surveillance
Voice active method
Environment voice filtering, directed human voice sensor.
Shock active method
Internal Shock active sensor.
Device configuration method
Password protected SMS Text message
Active way
Voice active alert through SMS and call back.
42x33x8 mm
Charge voltage
5V-6VDC 500mA
Charger input volt


User's manual Download: