The lock sound is a small click on the iPhone power button when you press it to turn it on or off. It is not a notification or ringtone and cannot be heard if the device is muted or on silent mode. It can be helpful to some users as it provides auditory feedback when the screen is locked, but others might find it distracting or unnecessary. The good news is that the sound can be turned off by changing a setting in the Settings app.
To disable the lock sound on your iPhone, open the Settings app and navigate to “Sounds & Haptics.” You will see the option for Lock Sound at the bottom of the settings menu. Turning this toggle switch off will silence the lock sound and keyboard clicks on your iPhone.
You can also disable the lock sound by flipping the physical Ring/Silent switch on the side of your iPhone. This will also disable other system sounds, such as the phone ringing and text alert tones, and will prevent you from hearing notifications played by apps. To enable the sounds again, simply flip the switch back on.
It is important to note that turning off the lock sound may slightly reduce your battery life as it requires more of your phone’s internal resources to keep the screen on and run the other functions of your iPhone. If you want to conserve your battery but still be able to hear all of the other notification sounds and alerts, you can do so by adjusting the ringtone volume in the Settings app.