Microphone signal attenuating apparatus for oxygen masks

摘要

The microphone of a breathing mask such as an aircraft flight crew oxygen mask is disabled during inhalation to prevent transmission of air flow sounds. In the preferred embodiments, selected mechanisms determine when breathable gas has been delivered to the mask and in response, disable the microphone by disconnecting it during this time. In another embodiment, a cover shifts into position over the microphone to prevent or reduce reception of sounds thereby during delivery of gas to the mask.