This is quite true actually - another PES 'reinterpretation' of the game that indeed we had all became accustomed to - every single kick, pass and header was quite loud.
There's a fairly easy solution for both games:
First thing I would always do on PES was go into Sound Settings and turn the Commentary all the way up and then turn Sound Effects down to about 1/4 - this would tone down the annoyingly overdone 'boot' of the ball to something somewhat realistic (unfortunately the ref's whistle was hard to hear as well but it was a tradeoff).
Likewise the first thing I did with FIFA was go into Audio Settings and turn the PA, Player Calls and SFX volume down to half and then the Crowd volume down to one notch below half - this gives the best reproduction of the sound of an actual televised match in my opinion - crowd is still audible yet the announcers come thru very clear above the din and the sound of the ball being kicked is audible on booming keeper kicks and long balls and forceful strikes and clearances (and you can still hear the ref's whistle).
This is on 5.1 surround though and also my own personal preference so your mileage may vary - simply turn the SFX up a notch or two to your liking if you want to get that PES 'boom' of the ball back.
