Anyone having a muffled sound from the external speakers?

[badelhas]

I love my M8, I have it for 2 years now and stil dont find the need to upgrade anytime soon, best smartphone I ever had (and I had a few), I just hoped HTC would somehow upgrade it to Android Nougat, but I have low expectations regarding that. Battery is failing, of course, which I will take care of in the end of the month, and I dont know if its my impression but the external speakers sound muffled. I am hoping that the repair shop that will change my battery can somehow resolve that maybe blowing some compressed air on them, it can be small dirt accumulated with time, right?
Anyone else experiencing this?

Cheers