A complete installation should have a SOUND\SPEECH folder containing large .bin or .vpx files for police chatter.
Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\EA Games\Need for Speed Most Wanted . Nfs Most Wanted All Sounds Cutscenes And Cop Speech Fix
Usually delivered as a simple .dll or script file (like an ASI plugin) that works instantly with the widescreen fix and other modern wrappers. A complete installation should have a SOUND\SPEECH folder