Thread: [Ideas] Sound or app that keep dog away
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sulu is offline sulu
2011-11-30 , 10:02
Posts: 915 | Thanked: 3,209 times | Joined on Jan 2011 @ Germany
#33
Originally Posted by Duffer View Post
According to a quick google scholar search http://www.freepatentsonline.com/y2009/0038664.html

Indicates at least 20KHz
At 20kHz it should also keep little children away.