PSA
Several hours into Dragon Quest Heroes, yeah, I should disable the sound emanating from my controller. Characters like to talk, a lot, and snippets of dialog regularly come through the DualShock 4’s speakers. It didn’t bother me much at first, but the voice clips also come out of my TV’s soundbar and the two audio sources are out of sync. It’s becoming an annoyance.
As far as I know, there are two ways to keep the voices at bay.
The quick way is to hold down the PS button, then select Adjust Sound and Devices. From here, you can mute the controller’s speaker under the Volume Control option at the top.
The other solution is specific to Dragon Quest Heroes. While in the game, press the Options button, then go to Misc., then Settings. Under Volume Settings, move the Voices slider to zero. Doing so will disable these dialog clips entirely — not just on the gamepad speakers — so you won’t hear them from your television, either. This method ended up feeling too sterile for my liking.
Hope that helps!