Light produced at this level is the optical equivalent of an overtone perceived by the human ear during the plucking of a piano or guitar string.
(Light; produced; L:at this level) (Light; is; the optical equivalent of an overtone) (an overtone; perceived; by the human ear; T:during the plucking of a piano or guitar string)
Light Light an overtone
produced is perceived
L:at this level
the optical equivalent of an overtone
by the human ear T:during the plucking of a piano or guitar string