Hi Sambkf. Thanks for elaborating! Seems a lot like the human condition which have principle conditions with distinct peaks. It is true to say "gone up drastically" is vague.

I was just quickly sharing a thought and didn't with to take the time to fully elaborate it on a comment. Assuming those who were intrigued by the idea would dig deeper :)

You've inspired me however. I will gather more research surrounding this idea and create a more founded idea. Given that my ideas on this are fairly immature as I was just told about this phenomenon. :)

Just something to think about. If

""the Didgeridoo frequency has gone up drastically"

It is the human 'playing' the digeridoo that is responsible for this increase...

My desire is to find out what is the source for these new peaks we're experiencing. Something that resonates with me :) Any suggestions?