Why is my Samsung tablet not responding to my voice, or playing sound

Hi thanks for the advice, unfortunately it didn't work. It took me two full days, but I finally cracked the case, lol. I was very frustrated at the end if it, that I was willing ready to throw the tablet in the fire place, I stopped feeling so hard on myself, when I brought it to the one place where it's there job to figure this things out, and even he could not get anywhere with it. I was sat down thinking, and it occurred to me, to plug in my earphones just to see, and believe it or not, therected was sound. Dust or debris had built up in the little plug in and the tablet was reading it as a pair of headphones were plugged in. I sprayed the hole with a can of that air for your keyboards, and voila, like magic, the sound was working. Unbelievable, however I made more problems for myself, in the process of figuring out the problem I had messed with every setting possible for sound and volume, and the sound may of started working again, but it sounded like a cat with a bird in its throat, lol, I certainly made a mess with all the settings, the music sounds horrific now, live and learn, never in a million years would of thought that it something to deal with the headphones, even more especially because I never use them. Anyway the puzzle is solved, maybe this might save someone else hours of frustration, maybe I'm not the only one this has happened to.