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).