Speak Across Accounts

I have some long-running scripts that use the Speak command to report status. I have three accounts. I use two of them for long-running processes. I’ve just installed Yosemite. In the past, I would only hear the spoken status when I was in the account where the script was running. Now I hear the speech no matter what account I’m in.

Has anyone else run into this? Is there a way to prevent speech from one account being heard while in another account?