How does the 8D audio effect work?
It automatically pans the audio from left to right and back over a slow, adjustable cycle, using the Web Audio API's stereo panner. A touch of reverb is layered in to add a sense of space.
Why doesn't it work through my phone's speaker?
8D audio is a stereo panning effect, it moves the sound between a left and a right channel. A single phone speaker plays both channels mixed together, so the panning motion disappears. Use headphones or stereo speakers to hear it.
Is 8D audio a real audio format?
No, it's a nickname for this auto-panning effect, not a file format or a channel count. The exported file is a normal stereo MP3 or WAV.