Some of this is fixed by upgrading to the latest map, as it includes pronunciation fixes for vocalizer devices.
Otherwise, see
this link to tweak voices.
Americans, do you want to have to throw away all your existing GPS devices, and be forced to buy newer more expensive ones? If not, contact Congress and the FCC, see here.
Current Tomtoms:
Samsung Galaxy S3, with Tomtom App 1.1
Map USA/Canada/Mex v900 + HD Traffic subscription
Prior Tomtoms:
GO 2535LIVE, GO1535LIVE, GO740TM LIVE, GO2505TM, GO 930, XXL540, XL350, Go 720, Go 510, One Limited Edition, One 2nd edition