Here is my thoughts

I suspect human voice as in a mother talking to a child is healthy and nurturing.

I know different vitamins are built up and broken down at different wavelenths or frequencies of light. I once found a chart showing the different spectrums of vitamin formation, but it is on my crashed pc which I need to get fixed before I can access it.

From previous research I found that the Hz is the opposite of the nanometer

375Nm = 750Hz and 375Hz = 750Nm

# Frequency Range of the Human Voice
* Voice range covers 300 Hz to 3500 Hz
* Most energy concentrated below 1000 Hz
http://www.kodachrome.org/salt/sunderst.htm

The visible light spectum consists of pure light between 375 and 750Nm

I would say all you need to do is see the nanometers in which vitamins are build and broken down at then reverse them on the 375-750 relm.

Balance the Hz as a light gives the CRI of the bulb and grow in the dark.