Update:
Fixed.

Major thanks to Brian G. for his help with this.

For all of those who are plagued by this sound problem here is how I fixed it:



I was missing msvcr71.dll from Windows/SysWOW64 (specific location for Windows 7 64 bit)

I found the msvcr71.dll download by doing a google search for the file for Windows 7 64 bit. (message me for the exact link)

As the instructions suggested, I placed the files in Windows/SysWOW64.

I started FSX, loaded the 727, then loaded it again and now my sounds work. :D