We have seen some other reports of this and our engineering team is aware and working on fixing this for the Jibos that have been experiencing this.
For the moment, if you see this, we recommend:
A. Tapping Jibo’s screen to bring up his main menu and then tapping “Bot Basics.” You can then quit out of bot basics by holding your hand on Jibo’s headbut the act of opening it should allow Jibo to hear again.
If that does not work:
B. Please reboot Jibo.