Dog barking in ultrasound?

Hi all,

I have a Dodotronic USB ultrasound mic (192kHz). I record into the Ultrasonic app on my iPhone, or sometimes straight into Audacity.

I’ve been messing around recording things. Was able to successfully record some bat calls. If I record, say, my small dog barking, there appear to be ultrasonic components to the sound. Same thing if I clap my hands.

To listen, I set a high pass filter at 20 kHz, then bring the ultrasonic components down into audible hearing range. There are little bursts of sound that are generated by the barks.

I know that some dogs can generate fundamentals above 20 kHz because there is a paper about whining that documents it. Not sure about barking. But I’m wondering if the fairly live hallway in which I recorded is contributing to this effect. Wondering if a noise in our hearing range can throw off overtones in the ultrasonic range.

Here are two images of spectra: the ambient noise in the hallway, and the dog bark a few seconds later. The mic was about 3 feet from the dog.

Do you think she is putting out that sound in the 14–38 kHz range? Or is it something about the environment or an artifact of recording? Something I’m missing?

Thanks!

Amanda

20Hz to 20kHz is just the nominal human window* in the sound spectrum.

The ultrasound you’ve recorded could just be harmonics of audible sound, rather than a fundamental ultrasonic frequency.

https://www.tnt-audio.com/casse/life_above_20khz.pdf #

[* that window is closing ].

Thank you SO much! This is what I hoped was happening; nice to know it’s possible.

Thanks for the article–fascinating, plus valuable information on rule-outs that I can use.

Amanda