Auto Recorder starts and stops the record function when sound of a sufficient level is picked up by the microphone. This feature saves valuable recording time by not recording periods when there is little or no sound.

PRO:
- Smart Voice-activated Spy recording.
- Mic calibration recorder.
- Stopping recording automatically.
- Live audio spectrum analyzer.
- Unlimited recording time.
- Date-based naming.
- Background recording (You can open other app while recording even when display is off).
- Built-in share memo (Bluetooth Drive Dropbox Email Gmail WhatsApp etc.).
- Audio files .wav (3GP AMR MP4) export over the USB.
- Supports any OS (Linux Mac OS Windows etc.) to playback using VLC.
- Landscape and portrait display modes support for Tablet.
- Show free space.
- Can set WAVE format (3GP AMR MP4).
- Can use the rear microphone.
- Can increase microphone volume.
- Can delete older records if you are running out of storage space.
- Can set the sampling frequency (kHz).

In telecommunications a voice operated switch also known as VOX or Voice Operated eXchange is a switch that operates when sound over a certain threshold is detected. It is usually used to turn on a transmitter or recorder when someone speaks and turn it off when they stop speaking. It is used instead of a push-to-talk button on transmitters or to save storage space on recording devices. On cell phones it is used to save battery life. Intercom systems that use a speaker in a room as both a speaker and a microphone will often use VOX on the main console to switch the audio direction during a conversation. The circuit usually includes a delay between the sound stopping and switching direction to avoid the circuit turning off during short pauses in speech (From Wikipedia).