The LS-P4 Audio Recorder from Olympus features three microphones and is designed to mimic the function of human ears. It is equipped with two directional microphones to create a stereo effect with a third omnidirectional microphone that is positioned between the other two on the recorder. It can be used to capture an expanded frequency response of 20 Hz to 20 kHz when the center microphone is on, and 60 Hz to 20 kHz when it is off. The LS-P4 PCM recorder is compatible with FLAC format recordings that reduce high-resolution audio file sizes with no reduction in audio quality. Other features include compatibility with PCM/MP3 file formats, USB charging, built-in 8 GB file storage (which stores up to 253 hours of audio), a microSD external memory slot, and Bluetooth playback on compatible headphones.