Plantronics 400 DSP digitally enhanced foldable stereo headset with full-range stereo sound. The foldable design allows for easy storage and transport. Listen to your CDs, DVDs, or MP3 files. Its microphone enhances speech accuracy. Plantronics PerSono Audio Control Center Software available via internet download. The PerSono Audio Control Center Software allows users to adjust microphone and audio characteristics like volume, bass and treble, launch their favorite voice or audio applications, as well as select audio presets like rock, jazz or classical, all from a central software interface.