New Unknown Sound on My iPhone 12 Pro Max

I previously owned an iPhone 6s+ and finally decided to upgrade a little over a year ago. I chose the iPhone 12 Pro Max Plus and I have been using it for over a year, but just recently, my iPhone has started making an unusual and unrecognized sound. I have not been able to determine why it is making it and I have not changed anything "that I am aware of". The sound is somewhat random and it sounds like "dedunk"???

I don't use my phone for too much more than a phone and a camera. I do text occasionally, but not constantly.

All of the Non-Default Apps that I have installed have not changed.

About:

iOS: 16.7.2

Model: iPhone 12 Pro Max (MG9F3LL/A) Unlocked

Capacity: 256 GB

Available: 226 GB

Carrier: AT&T

Settings:

Bluetooth is off

Wi-Fi is off

Hotspot is off

No Focus

No Screen Time

No Siri

No Face ID

No Calendar

No FaceTime

No Health Data

No Music

No TV

No Game Center

Non-Default Apps Installed:

Bible

Bible Commentary

Bible - Parallel Plus

SKJV

Bushnell Trail Cameras

BJ's Wholesale

Unit Converter

DuckDuckGo

Ewing Outdoor

Firefox

Google Earth

Google Maps

Sam's Club

SiriusXM

I imagine that this is something simple, but after several searches, I have not been able to figure out the cause or the proper set of search terms......

If anyone has any ideas, I am open to suggestions.

Thank you for your time and efforts!

Bill