Hi okie1951,
We're happy to help out so you can hear the alerts when messages arrive for the two contacts. It sounds like Hide Alerts has been enabled and just needs to be changed back to Show Alerts.
Follow steps below, and when you tap Hide Alerts, it should disable the muted contact. For more details see Change message notifications on iPhone.
Mute notifications for a conversation
1. In the Messages list, touch and hold a conversation.
2. Tap Hide Alerts.
You'll want to select "Show Alerts" instead of "Hide Alerts".
That should allow the alerts to come through again. Let us know if you still need help.
Cheers!