Hello KEG1962, thank you for posting and sorry to hear you are unable to hear your characters in-game.
First of all, could you please check what audio device you have listed for audio output in the games settings?
Some of our titles do not make use of all of the audio channels used by modern speaker and headphones, such as 5.1 and 7.1. Certain channels such as voice or sound effects, may be hard to hear if using a multi channel audio device such as surround sound or virtual surround sound headphones.
Once you have confirmed you have the correct audio device selected in the games menu, please follow this troubleshooting guide for PC -
Please let us know how you get on after trying these steps provided by Microsoft.