Like you I also had the same problem with my neighbor and his dog. Went thourgh the same routine. In the end I also bought one of those anti-barking devices. The problem was one of distance. The dog was just too far (about 200 ft) and the maximum range was less than 100 ft. So originally I recorded the anti-bark sound on my PC. First of all, sampling and frequencies all had to match. As an electrical engineer, I know somehting about sampling theory, etc. So, I used a freeware from audacity.com because it allows me to set the sampling rate, to record, to do spectral analyses, and to export in a variety of formats. spectral analysis showed signal power below 20khz. Dogs can hear to about 40khz, so I made my own recording using audacity software. First I set a sample rate of 96khz, then I created a 30 second sweep from 15khz to 30 khz. Second I created a downsweep from 30khz to 15khz, then I mixed the two creating essentially a flat spectrum from 43khz to 0khz. Then I used a high pass filter to pass everything above 15khz. Spectral analysis, which I cannot include here but can send by e-mail, showed an essentially flat spectrum from about 12khz upward. I then burned a CD, played it on my CD player through a high freq. amplifier (30khz bandwidth) and then through an array of 12 piezo electric tweeters flat to 30 khz.
I used my PC to record the output from the speakers in order to do spectral analysis on the actual output and discovered that either the CD player or the production software of a sound CD band limited the signal to about 17khz. The specturm showed the signal aliasing at about 17khz. So I played the signal straight out of my laptop pc to the amplifier/speakersk did the spectral analysis and found that I could produce a signal flat to 43 khz this way ie not using the CD player.
The signal is very effective. the dog stops barking and always runs for cover. The system works both from the CD and from the laptop although the laptop signal has a higher bandwidth.
Conclusion. Yes, this approach does work very well but one needs a high frequency amplifier (car amplifiers good to 30khz are availabe quite cheaply) and also high frequencyt piezo electric tweeters (about $1.50 each), an array is absolutely necessary to increase actual sound power.
Barking is generally considered a normal behavior that most dogs display. Some breeds tend to bark more than others, and domesticated dogs seem to bark more frequently and for different reasons than wild dogs. Barking is, after all, a method by which dogs communicate with one another and with their human companions.Dog Kennels..
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Wow! Thank you very much for the post and congratulations for your success. I also thank you for reassuring me that
I'm not the only person in the world crazy enough to try this sort of thing :-). You obviously have me beat :-).
Even though I'm not sure if the average, non-EE, type person would be able to follow what you did, I hope that
somebody might read this and be able to get something out of it. I am very impressed and have many questions for
you. I ask these questions not only to satisfy my own curiousity, but in case someone does read this and try it for
themselves. And yes, I would love to see your spectral analysis. You can email it to info@ihatebarkingdogs.com.
1. I am curious to know what kind of soundcard you have that was capable of supporting a 96KHz sampling rate. I know
that many professional sound cards support higher sampling rates but most consumer level cards only go up to 44.1K.
2. You mentioned the use of car amplifiers that were good to 30K. You said that you measured freq response out to
43K so you must have used something else. Can you tell me what amplifier you used or did you purpose build one
yourself? Also, if using a car amplifier, one would need a 12VDC power supply.
3. Did your measurements include any SPL data and power requirements to achieve any given average SPL's at those
high frequencies. Also, could sliding up the Hi-pass frequency above 15K make it less audible to some people
(younger ones) and reduce power requirements at the same time.
4. What kind of configuration did you use for building the array? Series? Parallel? a combination of the two? I
assume you had to do some sort of impedance calculation. Or did you just make sure that the impedance seen by the
amplifier was not below it's rated safe operating load.
Yes, when I came up with the idea for the BarkstopCD, I had to deal with the same Nyquist/aliasing issues that
you've discovered. Twelve years ago when I started experimenting with this, over-sampling was not very common.
That's why I chose the 3 different frequencies. Knowing that there were CD players out there with different
brick-wall anti-aliasing schemes, there was no way to know what kind of player the CD would eventually be played on.
I also used to experiment with piezo electric transducers as midi triggers. They worked very well.
Mike
Mike,
I sent you an e-mail to the info address with various photo attadhments. Any thoughts?
Vic
Barking Dogs can be one of the most annoying issues for neighbors. By all means attempt to work with your neighbor. Below are some suggestions towards how to work with barking dogs.Should all else fail, then you may need to fill out an animal complaint form. That can be found at the end of this page.
Dog Breeders
Vic,
That was what I had in mind. I've been using 2 different types of electronic ultrasonic bark control devices with no luck. I would like to try your approach as my final attempt to stop the neighbors dogs from barking.
Can you please provide a parts list for all the items needed?
Thanks and great job!
Tom
Tom,
Sorry for the delay; I had not checked the site in weeks. Here is my list of parts: Amplifier Pyramid PB440x, 240 watts 12 v. Pyramid PS--91-KX, 12 v regulated power supply. 12 piezoelectric tweeters with response to 30Khz. available widely for less than $1 each, CD player. You can easily double the number of tweeters, say 12 per channel for even more effect. e-mail me at vicandtj@verizon.net so we can discuss more design options.
Vic
I sent you an email with some information. Hope to hear from you soon.
Thanks!