I get a sharp metallic sound from some units

[Kevin]

This usually happens when I play as the Romans. Sometimes, while playing a battle, I tell a unit to advance and the captain/general says something but then instead of a response from the unit, they make this sharp almost-metallic sound. It's really weird but only happens sometimes. I though I might have done something wrong during the download but I downloaded 1.2 again and it still happens. How can I fix this?

Edit: It also happens after the general uses Rally