Plantronics Vista Plus DM15 digital adapter utilizes 2nd generation technology & DSP (digital signal processing) to deliver unsurpassed levels of acoustic protection & exceptional sound quality. With Sound Guard DIGITAL, daily personal noise exposure is monitored & automatically controlled to aid compliance with new EU legislation. Constantly on guard, Sound Guard DIGITAL also identifies & eliminates sudden loud sounds, to avoid user discomfort. Plantronics Call Clarity DIGITAL combines a range of techniques to enhances sound quality. It's automatic volume leveler maintains a constant listening volume, regardless of incoming call loudness. Selective frequency-response shaping maximizes speech intelligibility, whilst phone-line noise is also reduced. Product Features Sound Guard DIGITAL acoustic protection: Anti-startle processing to remove sudden, loud sounds. Daily personal noise exposure control. Call Clarity DIGITAL for optimum sound quality: Enhanced speech intelligibility with selective frequency-response shaping. Phone-line noise reduction. Automatic Volume leveller. Volume, mute & tone controls. Compatible with all major business phone systems Compatible with all Plantronics Call Centre & Office headsets Headset / handset switch