To put this in different words, you're basically asking about steganography applied to a radio transmission. I think the answer is: unlikely to be noticed unles

To put this in different words, you're basically asking about steganography applied to a radio transmission. I think the answer is: unlikely to be noticed unless you were receiving particular attention for some reason. Though your noise might inadvertently violate bandwidth constraints. If you search for radio steganography or acoustic steganography you'll find a bunch of papers on the topic.