my questions are :
1_ how could i generate an ultra_sound wave at 3000_3600 Hz/adjustable frequency .
2_could i make the sound appears on microphone or any thing that make waves separeat in the air
and thank you again mr hgmjr>>>>>>>>>
1) That frequency range isn't ultrasonic, it's quite audible.
2) Any common small loudspeaker, preferrably a tweeter, will reproduce those frequencies.