For example, you could make your bedroom Echo have “Echo” as its wake word, have your bathroom Echo be “Alexa” and your living room Echo be “Computer.” That way, when you say “Alexa” only the bathroom one will pick up what you’re saying, when you say “Echo” only the bedroom one will pick up what you’re saying, etc. It takes a few days to get used to the different wake words, but after you get used to it, this problem is totally solved.
To change the wake word on an Echo device, say “Alexa, change the wake word” and then select the new one when prompted. You’ll have to do this on all devices for which you want to change the wake word. It’s super easy though!