voice information. and inside it we have this acoustic. this is sending out -- >> this is the thing of the hour that we're trying to sense. >> this is what the whole world is hoping to find. this is inside this box. it's sending out an acoustic signal, not radio but noise essentially. this is in-water to be detected. >> what's most fiing to everybody is that neither of these were picked up, detected, et cetera. i want to show you something here that actually caused me a little bit of a concern. >> okay. >> that's an on/off switch right there. >> right. >> that's an on/off switch. i could easily flick it off. we know there are four of these elts on board the plane. would it be easily accessible and could you switch them off? >> one is in the cockpit. listen, so it's off. or it's on sort of stand by mode where it's -- if it gets a certain g-load, meaning if the plane hits or stops abruptive, then that will activate it. that's a crash, essentially. or you can just turn it on. there might be a situation where