A patent, filed in March 2016 and unearthed by Patently Mobile, points to exactly that, with a speaker in the top of the pen allowing sound to be played through it.
When the S Pen (or Galaxy Note Pen as it's called here) is slotted into the handset it could even double up as a speaker for the phone.
What's the point?
What the patent doesn't really explain is what the point of any of this would be, but possible uses could include having notes you've just taken read back to you, or sound an alert and help you locate the stylus next time you lose it down the sofa.
If the built-in speaker coexisted with the handset's speaker it could also allow for louder audio out of your smartphone.
As a patent there's no guarantee that anything will come of it, and even if we do see a speaker stylus in future it's unlikely to arrive before the Samsung GalaxyNote 8, but it makes sense that Samsung would be trying to do more with its stylus, especially now Apple has started making a stylus of its own.