Infrasound Time Lapse, 30x C-store using DS Lite Mic

This is a recording at a convenience store I made with my Nintendo DS Lite using a homebrew program I wrote. It records at 8 kHz sampling rate then uses a Fast Fourier Transform to down-sample by a factor of 32, resulting in a sampling rate of 250 *HERTZ* It can record about 2 hours in a little less than 4 megabytes. I saved the recording to the SD card then used my PC to speed it up by a factor of 30, resulting in a 250 hertz sampling rate played back at 7.5 kHz. You can hear the refrigerator compressor cycles, automobile engines, and the door slamming. The spectrogram was generated with Sonic Visualizer. The top end of the spectrogram is 125 hertz, and the lowest frequency the microphone records is about 2 or 3 hertz.

Category:

Science & Technology

Tags:

• infrasound
• bass
• microphone
• Nintendo
• DS
• Lite
• convenience
• store
• homebrew

[beatsiz]

This is so much higher than 250Hz...

[Amishman35]

@beatsiz The sound you hear in the video is going 30 times faster than it normally plays.

[bigfooter109]

what is the program called?

[Amishman35]

The spectrum analyzer is called Sonic Visualizer, and to get the sound I used a homebrew program I wrote for the Nintendo DS.

[beatsiz]

@Amishman35 Nevermind, I didn't understand the process you went through to achieve the sound you got but now I understand way more about Infrasound and Audio.

[UnderManiac]

Infrasound is anything below 20Hz