My brother recently bought me an Alexa for my birthday. He thought it was a great joke because both my wife and my daughter are called 'Alexa'. However this has caused chaos in family conversations as every time anyone addresses one of the human Alexas in the house the Echo unit wakes up and starts talking or playing arbitary music. We have it located in the kitchen but it can even hear talk in other rooms too. Is there any way I can change the word the Echo wakes up to?