ADR-0044: The Music Is Turned Down While a Request Is Heard, and Comes Back by Itself

Context

The reSpeaker’s XMOS chip cancels the echo of its own speaker, not of the stereo. With an album playing beside it, a request asked over the music was heard as speech until its six-second limit, sent at twice the size, and written down with the music in it (CHG-0037). Smart speakers lower their music while they listen. EdS’s music comes from players EdS controls.

Options considered

Pause while listening. One command, and silence is best for hearing. A wake word heard by mistake stops the music, and resuming is only right if nothing else was asked for.

Turn the volume down to a quarter, and back. The music never stops, and a mistaken wake is a moment of quieter music.

Do nothing, and let requests over music run long and be misheard.

Decision

The device says it woke; voiced asks for the music to be ducked; the player’s driver turns it to a quarter and brings it back by itself.

• voice/<device>/woken, {"v":1}, never retained, is published the moment the wake word is heard. The device still commands nothing.
• voiced sends duck on nowplaying/command when it hears it, and unduck once it has answered the request, understood or not. nowplayd passes both to the current source, as the buttons are passed.
• The iTunes driver ducks to a quarter of the volume it finds, and keeps what it was. It comes back on unduck; before a play_album starts, so the album is not quiet; and by itself ten seconds after the last duck, so a request that never comes cannot leave the room quiet. A duck while ducked lowers nothing further and waits ten seconds again.
• A volume press while ducked ends the duck where it is: whoever pressed it has taken the volume over, and nothing is restored over them.
• A source that cannot duck says so, as for any command it does not take. The turntable takes no command at all.

Consequences

• The music dips at every wake, a mistaken one included, for up to ten seconds.
• The first half second of a request is still over the music: the duck is three hops away, through the broker.
• Two more commands on the bus, from voiced’s account, which already may publish nowplaying/command.
• Each account gains one grant: the device’s to publish woken, voiced’s to read voice/+/woken.

What would settle it

Tested against stand-ins: a duck lowers to a quarter and remembers; unduck, play_album and ten seconds each bring it back; a duck while ducked lowers nothing; a volume press ends it.

Not yet shown:

• On the real iTunes: a wake dips the music, and it comes back.
• A request said over the music ends at the quiet and plays.