The method 1, wherein the two different frequencies are {TAIL ~ a first frequency} of about 1 to about 100,000 Hz and a second frequency of {HEAD ~ about 0.0001 to about 10 Hz} and the second frequency is lower that the first frequency 
The method 1 , wherein the two different frequencies are { TAIL ~ a first frequency } of about 1 to about 100,000 Hz and a second frequency of { HEAD ~ about 0.0001 to about 10 Hz } and the second frequency is lower that the first frequency
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH