From Ask.Audio:

"The frequency of the heart fluctuates between approximately 1 Hz to 2.5Hz. It does not have a steady frequency that can be multiplied to achieve 432 Hz.

Brainwaves or Neural Oscillations range between approximately 1 Hz and 70 Hz and are not tuned to 8 Hz or other divisions of 432 Hz in any way.

The Schumann resonance is a set of electromagnetic oscillations that originate from earth. One of them currently resonates at an average of 7.83Hz and not 8 Hz. which if multiplied by 55 gives us an A=430.65 Hz. Close, but no cigar.

Astronomers at Stanford have recorded super sonic oscillations from the sun at around 5.964 GHz. They had to slow them down (change their pitch) by 42,000 times to accidentally hit the frequency of 142 Hz - and not 144 as claimed by some which would again bring us a frequency of A=426Hz.

Water molecules can vibrate in a wide band of extremely high frequencies close to the infrared spectrum (90–110 Tera Hz). The band is wide enough to not favor any specific frequency, let alone 432 Hz."

They conclude "432 Hz seems to be just another number without any special significance over others."

As for me, I reckon there may be some special significance to the Schumann resonance, because we evolved in it.

Interesting challenge. I'm glad I looked it up. Thanks!