This is probably because of the stimulation of the meridian system of the plant at the range it is most “vocal” in, 100 hertz, which causes the plants to increase their output at that frequency threefold

Found that here:
http://sps.nus.edu.sg/~tanshenm/2171.pdf

Also found this:
The perceived pitch of a person's voice is determined by a number of different factors, not least of which is the fundamental frequency of the sound generated by the larynx. A person's natural fundamental frequency is influenced by many factors, including the length, size, and tension of the vocal folds. In an adult male, this frequency averages about 125 Hz, adult females around 210 Hz, in children the frequency is over 300 Hz.

from: Vocal folds - Wikipedia, the free encyclopedia

So maybe this explains why Bob Marley works well for you SnS...I find it very interesting...I may be right....but for now....:smokebong: