When my Nexus 5 says speak now, and I speak, it doesn't hear?

[AC Question]

when my nexus 5 says "speak now", and I speak, it doesn't hear.

I hit the mic button on the upper google-bar of my nexus 5(4.4.4), and the "speak now" prompt appears. After speaking and waiting(no response), it prompts to hit the mic again or say "OK google". It then gives no response to "OK google", but responds to my tapping to mic--with a new "speak now".
Where is my 5 minute response--it's been over 30 minutes