Sorry if this is a bit late but i found the solution! and made an account to tell you
i have had the exact same problem as you except i have vista so i cant install starforce so i need to use a no-cd as well i have been trying for 2 days and i found what the problem is. It is with the no cd you are leaving out a step with the installation
once you copy the contents of the no-cd (assuming you are using the same no-cd crack as me i am also using 1.1 version) go to the root of GT legends in the folder there should be a file called decompress.bat or something like that open that and it will decompress all the sound files. and there you have it sound works great. i am sure this will work for you too.
I hope this helps you and all other people who have this problem and Googled it like me.