Full-spectrum microphone idea

[Stefano]

This isn't related to UV/IR photography, it's a very "out-of-the-box" idea but I wanted to share it.

 

I stumbled upon this video:

 

This is a pretty expensive ($2500) microphone that can hear up to 100 kHz, in the ultrasonic range. This could be used to "hear the inaudible" much like our cameras can "see the invisible". In the video there are some experiments on that (like hearing dog whiskers).

 

Pairing such a microphone to a full-spectrum camera could be an idea, simultaneously seeing and hearing outside our senses. I can hear to about 16-16.5 kHz.

 

Sound filters (bandpass, longpass, etc.) can be easily made in software by removing the desired frequencies (Fourier transform).

 

Maybe some members will be inspired and post the results... who knows. Just sharing the idea.

[dabateman]

I researched into this briefly when I wanted to see if a mouse speaker was working.  You definitely buy cheaper devices,  and couple them to free software.  I think it was around $200 for the microphone.  Mice get mad at high frequency,  and that is common for some deturant systems. 

I never ended up buying it, as spending over $200 didn't seem worth it to see if a $60 device was working.

[Andy Perrin]

Interesting video. I still like the idea for an "audio camera" to turn an array of microphones into a visual picture. It would need to be pretty big, though, given the long wavelength of typical human range sounds.

[Stefano]

At 100 kHz the wavelength is about 3.4 mm, which is short but still quite long. At least at shorter wavelengths sound becomes more directional since it diffracts less, behaving more like light (sound starts to behave like rays). You could mount the microphone to the end of a tube to make it directional, and scan an area.

[lukaszgryglicki]

My father works with non-destructive imaging using ultrasound - but frequencies there are over 1 Mhz. He works for railways

[Andy Perrin]

Yeah you get much better images at ultrasound frequencies. But I like the idea of having a human audio frequency “picture”. I think it would be fine for landscapes, just not portraits. Even with all the diffraction. 

[lukaszgryglicki]

With several MHz frequency you can even make a portrait.