This still doesn't give a definite answer to the question of how the whispering ".profile" file got there in the first place. Unfortunately, that's nearly impossible to figure out without a detailed examination of the entire disk, along with a bunch of answers to questions like what websites are visited, what web services are used (e.g. Dropbox), what matlab modules are used, and so on. That's a time-consuming and expensive process, at best. And it may not even come up with an answer.
The very likely answer is that someone in close proximity added the speech command to the profile, as a joke.
But while you're at it, why not check the fsl.sh file as well then? It was modified one day after the rest of the files in the bin folder.