Argh. I am sitting in the train going to work and have attached today headphones to my fancy iPhone (iOS 11.4). Last days I played in the train without sound, sometimes holding the phone to my ears to listen what that crazy clown says.
But with my headphones I only hear the music? Is this a bug or can I do something?
Well, I could have played now another 10 minutes without sound, enjoying this work and kids free time of amusement in the train. Instead I created this post.
Just to clarify: did you always hear the background music and sound effects, when you use your headphones, or sometimes you did not hear even the music?
Also might be worth checking:
Options > Text and Speech > Hear Voice
To make sure itâs selected. It probably is if it was working before, but you never know!
Doesnât the mobile version start up with deactivated sound? And hadnât Ron mentioned somewhere that he canât detect headphones? 
I checked the preferences, and sound and speech is OK there (also the toilet paper setting). As soon as I attach the headphones, no speech. Iâll have to test later other headphones.
Seems really weird, but it definitely isnât the first time:
Good boyâŚ
In real life hands down over, but visually in game it looks better under. 
Iâve always been an âoverâ gal, though thinking about it âunderâ does make a bit more sense (in either world) because then you get a little âflickâ that invites you to pull off a sheet. Whereas âoverâ is a bit withdrawn and shy.
I may be 'overâthinking this.
Erm, are we using the same terminology? Itâs âunderâ thatâs shy.
I meant âshyâ in that it extends itself away from the, er, customer.
Itâs interesting how (fast) we got from headphones to the orientation of toilet paperâŚ
Exactly. Under is further away from you. >_>
Yeah, but âunderâ curves towards you.
But that makes it more difficult to rip off one piece of paper.
Does it? Why?
Try it. You will recognize the differences much more drastically If you use only one hand to rip off one piece. (*)
(*) Is that a valid sentence? Man, I have to go to sleep. But this espresso from @milanfahrnholz was hard stuffâŚ
Because with the other youâre holding your phone to post here?
Putting a shot of Paddy´s in was perhaps counter productiveâŚ
That is very perplexing. Speech is handled no different from music or sound. Itâs all just wav bits passed to the same system. Iâve looked at this over and over and I canât see how plugging headphones in would change anything. Even if iOS was doing something odd, by the time iOS sees the sound data itâs one merged stream.