Said for the eleventy gorrillionth time.
It could equally be something like this. We need to expand our thinking.
Whales (and I believe submarines too) have used ultra-low frequency sound waves to transmit data, as they can travel father through water.
Whales have been known to communicate over thousands of miles.
Is there an audio file of this wave anywhere?
You mean like Frequency Modulation, as opposed to Amplitude Modulation?