pi@raspberrypi ~/PiFM $ dd if=/dev/zero of=sound2.wav bs=7215 count=1
1+0 records in
1+0 records out
7215 bytes (7.2 kB) copied, 0.000788972 s, 9.1 MB/s
pi@raspberrypi ~/PiFM $ time sudo ./pifm sound2.wav 100.0
exiting

real	0m10.000s
user	0m0.010s
sys	0m0.330s
pi@raspberrypi ~/PiFM $