How to turn off speakerphone<br>Turn off speakerphone during a call. It is important to know how to turn off speakerphone during a call without hanging up on the caller on the other end. [substeps] Tap the round, highlighted speaker button on your iphone screen.
Turning off the speakerphone during a call on an iPhone works the same as how your turn on the speakerphone during a call. 
I can guess that this is true, but it is possible that activating speakerphone requires a different step than deactivating it. 