A software problem is among the most frequent causes of too low loudness on iPhones. This may be due to an iOS system error or an issue with a particular app you're using. In certain circumstances, rebooting your iPhone will solve the issue.
Causes of Problems With Android Phone Volume
Your phone is tethered via Bluetooth to another device that plays sound. An app is running in the background that controls the overall volume. Do Not Disturb Mode is active. The speakers or headphones have hardware problems.
When you're on the phone or listening to songs, movies, or other media on iPhone, you can use the buttons on the side of your device to adjust the audio volume. Otherwise, the buttons control the volume for the ringer, alerts, and other sound effects. You can also use Siri to turn the volume up or down.
Frequently asked questions about volume limiters
From your iPhone, go to Settings > Sound & Haptics > Headphone Safety. Enable “Reduce Loud Sounds.” Set your limit between 75-100dB. You can choose your limit in 5dB increments.
Go to Settings > Sounds (or Settings > Sounds & Haptics), and drag the Ringer and Alerts slider back and forth a few times. If you don't hear any sound, or if your speaker button on the Ringer and Alerts slider is dimmed, your speaker might need service.
Just below the Silent switch, you'll find the Volume buttons, which adjust sounds for videos and music in increments. This also works if you're trying to increase ringer volume. If the buttons don't change anything, go to Settings > Sounds & Haptics, then check that Change with Buttons is turned on.