I made a post about this before, but only got one answer that did not help. I had my audio in effect first, but hated having to go to the first frame just to hear my audio. I asked about it and was told to make it to stream. Now I can not hear the audio at all from any point. I know many posts of this exist but those have not helped me. I tried making my audio to 48000 hz like one post said and I could not import my audio at all. Another posts said I needed to be in actionscript 3.0, but I am! I am not sure what I need to do now.
what kind of project? html5, as3, something else?
in any case, your sound file should use a compatible sample rate (the most common solution), eg. 44.1 khz or 1/2 or 1/4 of that. more info from How to use sound in Adobe Animate
However, mp3 sound data is compressed and smaller than WAV or AIFF sound data. Generally, when using WAV or AIFF files, it’s best to use 16-22 kHz mono sounds (stereo uses twice as much data as mono), but Animate can import either 8- or 16-bit sounds at sample rates of 11, 22, or 44 kHz. Sounds recorded in formats that are not multiples of 11 kHz (such as 8, 32, or 96 kHz) are resampled when imported into Animate. Animate can convert sounds to lower sample rates on export.
so, first thing to do is open and resave your sound with audition using compatible (with animate) settings. in my experience, that solves all sound file issues.
there can be other problems but working on those problems is a waste of time until you have a compatible sound file.
My audio file is 16 bit at 44100 hz. Still, when in stream, the audio does not play.
I would also like to mention that instead of seeing the sound waves, I only see a straight red line on the first frame.
extend the sound's layer for as many frames as its duration. no keyframes except the first.