Greetings, Lauraengleton.
Welcome to the Apple Support Communities. It’s understandable that you’d want to know how to get rid of the notification that an audio message was saved.
What happens if you delete the conversation?
“Delete a conversation
- In the Messages list, swipe left on the conversation.
- Tap Delete.” Delete messages on iPhone
Do the notifications appear when you start a new conversation?
We hope this helps! Thanks for being a part of the community.
Sincerely.