Your iPhone can help you relax, or SLEEP! How to play those sounds on iPhone 13 - HT Tech

The best part is that if you have an iPhone, you can play these sounds without downloading any third-party app, or subscribing to any other service.

Note that for the background sounds to play, you will need to have your iPhone updated to the latest iOS 15.5 version.

The iPhone by default provides six kinds of background sounds, three of which just try to imitate noise.

From the main Background Sounds page, you can also adjust the volume of the sounds, that too independently from other phone sound profiles.

You can also enable background sounds while playing other media on your iPhone.