B373.mp4 ⭐ Verified Source

: Located at the hand microphone to indicate selection made.

Based on technical documentation for the (often referenced as B737-3 or similar in training file naming conventions like "b373.mp4"), a key communication feature is the VOICE ONLY select switch . b373.mp4

: Automatically activates the oxygen shut-off valve when the mask is removed from its stowage box. B737-300/400/500 Boeing: Communications 23 | PDF - Scribd : Located at the hand microphone to indicate selection made

: The lower half of the switch displays a "C" to signal an incoming voice-only call. B737-300/400/500 Boeing: Communications 23 | PDF - Scribd

This is a momentary contact switch that, when activated (indicated by a green light), uses a voice filter to . This allows flight crews to filter out identification signals (like DME ident) so they can monitor voice communications more clearly across multiple systems simultaneously. Other notable functional features of this system include: