The company I work for makes electronics and has an EMI, not sure of the name, booth where no outside interference can get it. It's so we can test our products to see what kind of noise they output. I've been in it before when we aren't testing anything, therefore no outside signals are reaching me. I got a weird feeling. Not necessarily in a bad way, just weird after being in there a few minutes. It was a nervous calm feel. Would have been interesting to stay in it for a longer period of time to see if I noticed anything more. We certainly get bombarded with signals all day long and I've always wondered their effects.
All electronics emit noise of some sort. I can definitely see animals picking up on it.