why does speakerphone come on everytime?

[phil.i.stine]

Had my phone almost 12months without issue suddenly everytime i make/answer a call the speakerphone is automatically activated. checked all settings thoroughly cant find how to deactivate this. any ideas?

 

[BCwrangler]

Do you have any bluetooth headsets that maybe paired with your phone but not connected that may put the phone into speakerphone?