Review on Dive into Silence: Dogtek Sonic Bird House Bark Control Outdoor/Indoor - Enhanced Version by Elizabeth Lewis

I absolutely needed for work! I have a home nursery and an obnoxious chihuahua. I tried all day with six new batteries. In test mode, I could hear a piercing tone, so I immediately set it to low, then to medium, and finally to high with no effect. She seemed to flatten her ears once or twice to show she heard a sound, but it didn't bother her enough to stop her barking. I'm so disappointed because she has to stop barking when the doorbell rings or knocks or someone comes in the door, especially when she's sleeping. I've tried placing it in different parts of the house, with a spot right in front of where she sleeps and facing her directly. Unfortunately I will be sending it back and looking for something else.