If you have any sound issues with Jolla 1, while you are at it, replace original speakers with those suggested here: https://together.jolla.com/question/...comment=145763

I used the suggested Nokia Lumia 720 earpiece and HTC One X (S720e/G23) speaker (not earpiece). It was worth the upgrade, because with the original part, there was a crackling sound in the earpiece at loud volumes. It went away completely, and the loudspeaker sounds better, too. This was 1,5 years ago, still works fine.