A noise such as the roar due to traffic in a town may correspond physically in that it could probably be resolved into a nearly continuous series of wave-lengths, but psychically it is of no interest.
The clone groups live together, are psychically bonded, and the culture that thus arises is, while normal and healthy to those in it, rather creepy from the outside.
You might be psychically connected, such as being able to finish each other's sentence, or knowing what the other person is thinking just by looking at each other.