To answer an incoming call using the speaker function, press the clear key with a speaker icon rather than picking up the handset.
At any time you can take the caller off of speaker by picking up the handset. 
For a call in progress to be switched from handset to speaker, press the speaker key and then hang up the handset to resume the conversation in speaker mode.
To temporarily suspend a caller on speaker from hearing what is happening in your office, press the key with the microphone and slash to the right of the dialpad. This mute function is useful if you need to have a private, brief conversation with someone in your office. Then press it again to resume your 2-way conversation with the caller.
You can adjust your volume of the speaker using + or -
