What Is Headphone Safety on Your iPhone?
iPhones are entertainment devices.
Headphone Safety is enabled by default on any phone with iOS 14 onwards.

The default level is 85 decibels which is as loud as heavy city traffic or a food blender.
Apple has included this feature to limit your exposure to loud sounds.
Also, iOS excludes phone call volume in analyzing these sound levels.

Apple recommends you set the right unit pop in in iPhone’s Bluetooth configs.
This allows iOS to measure the optimum audio levels for the Headphone Safety feature to kick in.
How Do I Stop My iPhone From Turning Headphone Volume Down?

The iPhone manages sudden volume spikes with the help of the Headphone Safety feature.
Any volume above the default volume level or set manually by you on the slider is automatically reduced.
But there may be instances when you don’t want the iPhone to turn the volume down automatically.
For example, when you listen to music via Bluetooth speakers in your car or are hearing impaired.
Tap on the toggle forReduce Loud Soundsto turn it off.
Some region or operator-locked iPhones may not allow you to turn off Headphone Safety.
FAQ
Bose headphonesconnect to iPhonesusing Bluetooth.
First, flip the switch on the right earpiece.
Then, kick off the Bose Connect app, which will recognize both your phone and the headset.
Swipe down on theDrag to Connectmessage to pair.
If they don’t connect, make sureBluetooth is on.
First, try pressing theVolume Upbutton on the iPhone.
Otherwise, check to see if the headphones have independent volume controls on either earpiece.