From QB64.org wiki
The _SNDPLAYFILE statement is used to play a sound file without generating a handle, automatically closing it after playback finishes.
- _SNDPLAYFILE filename$[, ignored%][, volume!]
- Supported file formats are WAV, OGG and MP3. See _SNDOPEN.
- ignored% is an optional parameter , accepted for historical reasons.
- In versions prior to build 20170811/60, ignored% identified if a sound was to be loaded with "SYNC" capabilities, (-1 for true, 0 for false). This is true for all sound files in the latest versions, making this parameter safe to be ignored.
- volume! is a SINGLE value from 0 (silence) to 1 (full volume). If not used or outside this range, the sound will be played at full volume.
- _SNDPLAYFILE never creates an error. If the sound cannot be played it takes no further action.
- The sound is closed automatically after it finishes playing.
- When a sound will be used often, open the file with _SNDOPEN and use _SNDPLAYCOPY to play the handle instead to reduce the burden on the computer.
Example: Playing a sound file at half volume.
_SNDPLAYFILE "dog.wav", , .5