No offense bagua but if you really can detect sar value variations with your ear I suggest you try this out:
http://www.randi.org/joom/challenge-info.html
There's a million bucks in it for you ;)
Seriously speaking - the European Unions safety limit is 2w/kg in 10 grams of tissue. I bet the sar value should be tens or hundreds of times higher for any harm. So I suspect your pain was due to some other cause - I used to get a slight headache when using the original N-Gage that had a very high-pitched speaker sound.