The tech site Engadget is reporting that if you find Amazon Echo devices helpful, but their on-board assistant Alexa a little loud sometimes, you and Alexa can now whisper to each other. The so-called "whisper mode" allows you to use the same commands you'd normally tell Alexa -- such as "dim the lights" or "play some lullabys" -- but she'll be able to hear you whisper them. And Alexa will confirm those commands as she always does -- but will do so in hushed tones. While a handy bit of bedtime tech, the upgrade is actually teaching the assistants to listen and reply in kind to conversational cues, and reply in a similar tone of voice. For example, you wouldn't respond to a friend telling you something quietly by boldly proclaiming a response.