-50db for what format? If it's masked, then I'd say no unless it was headphones. Given the fact the subliminal audio for masked is much lower than the masked audio track, then it may not have much power at that volume.
Ultrasonic, due to the subliminal audio being much louder (at the level of the masked track's masking sound), is okay at -50db, but a bit on the quiet side.
Basically, up to -30db max is the loudest you'd want to go safely. I listen between -35 to -40 with headphones, at that level there's no chance of hearing damage, and it's still plenty powerful. The louder the better up to those levels.
Ultrasonic, due to the subliminal audio being much louder (at the level of the masked track's masking sound), is okay at -50db, but a bit on the quiet side.
Basically, up to -30db max is the loudest you'd want to go safely. I listen between -35 to -40 with headphones, at that level there's no chance of hearing damage, and it's still plenty powerful. The louder the better up to those levels.
