2014 Outback and Bluetooth phone volume

I have my cell phone connected to the car's Bluetooth and uses the controls 
on the steering wheel. When I setup the operation, add numbers and dial, the 
volume is very loud. Once the call is made, I can adjust the volume with the 
volume -/+ on which also controls the radio volume.

Is there a way to lower the volume for the 'phone operator?' TIA