Check that you have downloaded the navigation voice file in HERE Drive and the speech-language file in the Windows Phone settings. Here's how:
- In HERE Drive, go to Settings > Navigation voice and check that a voice file has been downloaded and is ready to use.
- Go to phone Settings > Speech and make sure you've chosen a speech language and that the speech file is downloaded. Tap the Speech-language setting to confirm that the speech file has been properly downloaded. You may need to download the speech file again if you've recently updated your phone software or reset your phone.
Check also that your phone's speaker volume is turned up.