To be fair its not just the youth, everyone who comes to Thailand and especially Bangkok will have experienced the pain of sheer deafening volume at some point or another.
There have been many times I have been sitting in a internet cafe and had to leave because of the hellish noise that has been coming from the pcs and the ( mainly ) boys who are playing half life or counter strike or ragnarok or any other on line game and who are shouting at each other over the noise of the sound effects - of course then they cant hear the sound effects so turn the volume up so have to shout louder to hear each other so............ Walk down the street and you are assaulted by cd vendors, mosques, shops, bars, buses, sales vans of one sort or another all with loudspeakers and or microphones.
Add in the noise from tuk tuks, buses, motorbikes, trucks, cars and people you are struggling to find a moments peace and quiet. Even in one of the few parks in Bangkok you cant really find peace as somebody somewhere will be yelling to their friend, playing karaoke or there will be something somewhere breaking the peace.
Maybe thats why the classrooms are battlegrounds as well in the war of noise and why the kids feel the need to communicate at top volume rather than speaking to each other.
Nothing in this country can be subtle, tourist buses ( I might upload a picture of one later :) ) are painted in the some of the most garish paint jobs possible purples, reds, blues, greens, whites, oranges..... and thats just the front! and of course there is a 1000gigawatt stereo or band at the back of each bus pumping out music.
Go into any bar with a live band and the music tends to be an 11 on the volume scale of 10. Why I dont know because you just hear volume rather than the band. An evening of shouting to talk to someone is not my idea of a good time but it obviously is someones as that is the norm rather than an exception. And another thing they stupidly do is put the band on at the same time as the football! WHY ???
But to get back to the original question, there must be a huge number of deaf or nearly deaf here because of this. And they are creating so many more its scary.