Unlocking Trophies does make a sound after all
Looks like Sony are improving Firmware 2.40 already. Yesterday on their blog they stated that currently you will not hear a sound when you unlock a trophy. Now this has changed already and its turns out that they now will make a sound when you unlock a trophy.
Speaking on the Official Blog Eric Lempel stated:
" How quickly things can change - there *will* be a sound effect when you unlock a Trophy."
While not a massive change, but some users will be pleased to here it.