Dynamic EQ, microphone frequency response 100 Hz–8 kHz optimal for PC wideband voice telephony (up to 6,800 Hz), hi-fi stereo (C5220, C5220 USB-C only) receive frequency response from 20 Hz–20 kHz, enhanced Digital Signal Processing (DSP), noise- canceling microphone, adjustable audio alerts with Plantronics Hub software (mute/volume)*