Abstract: A wearable audio output device that includes a microphone and one or more input devices detects an input via the one or more input devices. In response to detecting the input and in accordance with a determination that the input is a first type of input, the wearable audio output device adjusts a mute state of the microphone for a first audio function that uses the microphone without adjusting the mute state of the microphone for a second audio function that uses the microphone. In response to detecting the input and in accordance with a determination that the input is not the first type of input, the wearable audio output device forgoes adjusting the mute state of the microphone for the first audio function that uses the microphone.

Abstract: A system utilizing the central vacuum system in the dental operatory to exhaust analgesic or anesthetic gas from a gas administration assembly. The system includes a nosepiece fitting over the nose of a patient, an exhaust assembly for removing exhaled gas from the nosepiece, and an exhaust chamber formed around the periphery of the nosepiece for scavenging gas leaking through the facial seal at the rim of the nosepiece.

Abstract: A scavenging mask apparatus for administering gas to a patient, the apparatus comprising a nasal cannula for delivering gas to the patient's nostrils, a tube connecting the cannula to a source of gas, a nosepiece adapted to fit over the nose and cannula, and a tube connecting the nosepiece to a source of vacuum. Gas exhaled through the patient's nostrils or escaping from the cannula is scavenged by the air flow in the nosepiece, thereby minimizing loss of gas to the environment. The nosepiece is also provided with a plurality of holes in the underside thereof to scavenge gas exhaled through the patient's mouth.