steven chiverton
Senior Member
yes i admitted the tuning fork mistake it was 220 hz not 40 kilohertz anyhow the 30 khz sound is nearly like the tinnitus sound in my ears so its easy to compare it nearly as this was a tiny bit louder and bounces off walls like sonar and i can easily hear the variations of it when i wave my hand around in front of the piezo i have 3 frequency counter kits so ill check with each one when i get to it even though they all need to be calibrated but i trust they may be correct i trust you've herd the sounds of those electronic mozie repeller circuits if you have ya ears close to them you can still hear them just. i have one of these car reversing piezo alarms and its in my bajack capacitor circuit, gee i never herd of bats attacking with the sounds of them thats a first ever