By default, this is set to “Automatic,” meaning your phone will use the smaller speaker (the earpiece) normally, but will automatically connect to Bluetooth or headphones if you’re using them. Unless you’ve changed this in “Settings” previously, you won’t need to do this.
For iOS 12 or earlier, these steps will be slightly different. Go to Settings > General > Accessibility > Call Audio Routing instead.
If “Speaker” doesn’t have a checkmark next to it, you may be encountering other problems with your phone. Try changing the setting to a different option (e. g. , “Bluetooth Headset”), restarting your phone, and changing it back to “Automatic” for good measure. [1] X Research source
