Android Question play music or tts while calling

I've looked at similar things a few times in the past, it appears that this is something that Android doesn't allow.

from my experice I can tell that by mistake tts speaked while in a call ...but now I could not find how this was possible ...and I am still wondering ..I will come back with an answer . I was looking on the forum the solution to stop tts in a call because the opposite was happening .

Now I use ecid(https://play.google.com/store/apps/details?id=ekawas.blogspot.com) app on galaxy s3,it can read sms or read new email with tts while I'm calling with my friend and my friend can listen what it speak