How to fade out playing sound or start/stop without clicking/popping

[macbutch]

I've read the docs + tutorial (and #49) but somehow this isn't quite sticking in my head right. I have a list of .wav files and when the user clicks on one I want to load and play it. So far so good and that's proved very easy with beep - thanks!

What I started with was when the selected file changed I load it up and then call speaker.Clear() and then speaker.Play() with the new data. It works nicely but sometimes there is a bit of a click or pop (fair enough). I've tried to add a quick fade out over a few milliseconds but I'm clearly not understanding how the volume scaling works.

I have an effects.Volume using Base 10 (but 2 also doesn't seem to do what I want). So I've done stuff like this:

	for i := 0; i < 80; i++ {
		volume.Volume = 0 - float64(i)/2
		time.Sleep(1 * time.Millisecond)
	}

Then I

	volume.Silent = true
	time.Sleep(5 * time.Millisecond)
	speaker.Clear()
	volume.Silent = false
	volume.Volume = 0

	// skipping some resampling but I update the Volume streamer here.

	speaker.Play(beep.Seq(&volume, beep.Callback(func() {
		done <- true
	})))
     

Theres is some latency (unsurprising given 85ms sleeping!) but this doesn't really seem to affect my clicks much at all. I think I've missed something really fundamental here. Would appreciate any help you can give.