Why would you say its low? We would see a bump in spectral emissions not correlating to any of the normal spectral emissions we see. If there was a degreed of EM chatter in that region then we would notice it just fine.
Moreover its also fairly useful for us, albeit it less so.. 5 years to send a letter home might be quite annoying, but I think would still be done. Especially if we are talking about life with long life spanes or in the case of cryogenics where that time span might not be as significant as it would be for us.