Hey Almostnosupport,
We'd recommend reviewing the information in this article to help check your notification settings to determine if anything there has notification sounds enabled that could be causing this to occur: Change notification settings on iPhone - Apple Support
This article may help as well as it provides steps for changing iPhone sound settings: Change iPhone sounds and vibrations - Apple Support
"Set sound and vibration options
- Go to Settings
> Sounds & Haptics. - To set the volume for all sounds, drag the slider below Ringtone and Alert Volume.
- To set the tones and vibration patterns for sounds, tap a sound type, such as ringtone or text tone.
- Do any of the following:
- Choose a tone (scroll to see them all).
- Ringtones play for incoming calls, clock alarms, and the clock timer; text tones are used for text messages, new voicemail, and other alerts.
- Tap Vibration, then choose a vibration pattern, or tap Create New Vibration to create your own.
You can also change the sounds iPhone plays for certain people. Go to Contacts 
, tap a person’s name, tap Edit, then choose a ringtone and text tone."
If that doesn't help, you may want to provide some additional information about the situation.
Does this only occur when a specific app is open in the background? Which version of iOS is running on your iPhone? When the issue occurs, is your iPhone paired with any other devices, such as an Apple Watch, headphones, or speakers?
Thanks!
