Mysterious Speech Commands

I have an iMac 24in Intel 2.16GHz running Leopard. It sits on an secured Time Capsule wireless network connected to a Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem.

Once every evening for the past 3 nights, my iMac has picked up a speech command that isn't from me. The first night, Text to Speech announced "Send this to CL" which launched a mail draft. (There is no CL in my address book). After that I opened the speech commands window to see what was happening but nothing else occurred.

The next night, it was "meet with Jane Doe ??? at eight". (Ironically, I know "Jane Doe" casually but I have no meeting with her.)

Then last night, it was "What date is it?" and Text to Speech responded.

Would anyone care to hazard a guess what is going on? Interference from a neighbor's bluetooth? A provisioning problem at the cable company that's leaking data to my cable modem?

Is this happening at the same time each night?
Do you have a computer savvy roommate who likes practical jokes?
What do you normally use your Speech function for, why is it activated?
Are computers that others use on the same network?

The next time this happens, check the exact time on your computer clock. Then check the activity logs, Utilities/Console.

I will take a look at the logs, thanks.

It is happening at roughly the same time each night.

No computer savvy roomie.

Text to Speech is activated so I can hear important announcements when I'm watching full screen video or have various things read to me when my hands are busy.

Speech commands are activated so I can tell my iMac what I want read to me.

Only my iphone and some peripherals on the network. I do have a separate guest network set up, but but it is secured and and no one was using it.

Did you by any chance have the radio/TV on in the same room? The Speakable Items feature will sometimes attempt to interpret those types of sounds as commands.

I do have the stereo in the same room, but ruled that out due to punctuation. I couldn't imagine anything sounding like "meet with Jane Doe-Question Mark-Question Mark-Question Mark-at eight"

Nothing happened Friday, then one more incident Saturday and it has been quiet since.