dead zones, wind pushing the whistles, etc

[Mark Billadeau]

Okay, the geek in me periodically muses about the possible physical sources of such handler laments at trials (I've lamented about these as well). In the past (typically after certain trials) I have attempted to find scientific studies of such acoustic anomalies with only minor success. This time I found an article that described how, wind, temperature gradients, humidity, and topographies impact acoustic propagation (i.e. how well my whistle carries). The section of interest is: II. Transmission of Sound Through the Atmosphere (see page 4 of this pdf)

 

 

Physical Constraints on Acoustic Communication in the Atmosphere: Implications for the Evolution of Animal Vocalizations

 

Mark

 

[Sue R]

I'll admit that I didn't read that but, after watching a number of trials (most multiple times as I don't go to many but do make it to certain ones often), I am a firm believer that there are dead spots and that conditions can affect the effectiveness of whistles. I see it time and time again, numerous dogs, numerous handlers, different whistle styles and techniques - and runs coming to grief at certain locations in a field and/or under certain conditions.

 

Thinking of the stories of differing acoustics in concert halls makes the terrain plausible as the "culprit" in some instances. Also temperature seems to play a part, humidity, wind.

 

That's my story and I'm sticking to it.

[Gloria Atwater]

It's way too late for me to read something with that many syllables in its title, alone ... - but I will say I recently ran head-on into conditions in which my dog simply could NOT hear my whistles, due to wind.

 

I was at a friend's farm where we long have known the bottom third of her 600 foot pasture often seems colder than the top. Well, we had a particularly windy day the other day, but we went ahead and worked our dogs. My Nick did fine (driving practice) until he got down to that lower part of the pasture, and suddenly he seemed to lose his mind! No matter what whistle I gave him, he did anything but what I asked, which is totally unlike him. I walked down closer and he still kept acting like a goober. I went down within 50 yards of him and there hollered at him to lie the hell down. He looked startled, but lay down as I asked and then we resumed working, with me staying close.

 

Same thing again. I'd whistle commands and he'd noodle around taking the sheep wherever. So I walked right to him ... and realized that just in that brief 50 yards, the wind ripped any up-pasture sound completely away. Poor Nick could hear me whistling, but in the wind, he couldn't identify which whistles, so he was desperately trying to do something, hoping he'd get it right. The minute we retreated to the upper parts of the pasture, the problem went away.

 

It was interesting to me, anyhow.

Cheers ~

 

Gloria

[ItsADogsLyfe]

We used to work dogs in a field about 8 or 9 acres large. Huge power poles cut through the middle of that field and when the sheep and dog ended up under the wires (and they were quite high up)the dogs became deaf sometimes. If I was standing under them I could hear them buzzing. There were also other places in that field where it seemed the dogs could not hear.

And then there was that time I thought my dog was totally blowing off my away whistle and after resending a few times and him repeatedly trying to cross over after about 30 yards, I walked up and realized I was trying to send my dog off a small cliff. Not a dead spot, but coulda been a dead dog.