play a single beep (beep.js)

Question

i'm trying to create a "generative score" using beep.js based on some map data i have. i am using new Beep.Voice as placeholder for notes associated to specific types of data (7 voices total). as data is displayed, a voice should be played. i'm doing things pretty "brute force" so far and i'd like it to be cleaner:

// in the data processing function
voice = voices[datavoice]
voice.play()
setTimeout(function(){killVoice(voice)}, 20)

// and the killvoice:
function killVoice(voice) {
    voice.pause()
}

i'd like to just "play" the voice, assuming it would have a duration of, say, 20ms (basically just beep on data). i saw the duration property of voices but couldn't make them work.

the code is here (uses grunt/node/coffeescript):

https://github.com/mgiraldo/inspectorviz/blob/master/app/scripts/main.coffee

this is how it looks like so far:

https://vimeo.com/126519613

Answer 1

The reason Beep.Voice.duration is undocumented in the READ ME is because it’s not finished yet! ;) There’s a line in the source code that literally says “Right now these do nothing; just here as a stand-in for the future.” This applies to .duration, .attack, etc. There’s a pull request to implement some of this functionality here but I’ve had to make some significant structural changes since that request was submitted; will need to take a closer look soon once I’ve finished fixing some larger structural issues. (It’s in the pipeline, I promise!)

Your approach in the meantime seems right on the money. I’ve reduced it a bit here and made it 200 milliseconds—rather than 20—so I could here it ring a bit more:

var voice = new Beep.Voice('4D♭')
voice.play()
setTimeout( function(){ voice.pause() }, 200 )

I saw you were using some pretty low notes in your sample code, like '1A♭' for example. If you’re just testing this out on normal laptop speakers—a position I am often myself in—you might find the tone is too low for your speakers; you’ll either hear a tick or dead silence. So don’t worry: it’s not a bug, just a hardware issue :)