lifehack, yelling detector

Hi all, I was wondering about something. I live in a loud house, folks are quick to raise their voices. I know they have bark detectors for dogs, so I was wondering about a "yelling" detector.

Some thoughts, 1. should probably be something other than a loud alarm, that only agitates the yelling. output could be more subtle, i.e. a cheezy laser show or something.

  1. low cost, i.e. less than $100 in parts.

  2. mounted on ceiling, or perhaps wearable?

  3. filter out non-yelling sound sources, how? Should not have hair trigger. triangulation? waveform analysis? individual inputs for things like the furnace being on to adjust the "yelling" threshold?

Any other thoughts or implementation ideas?

If this works, I will need a passive aggressive detector next :)

you could use this to prevent the talk in the first place: http://hackaday.com/2012/03/05/speechjammer-puts-an-end-to-annoying-speakers/ :D

um actually on topic, i think a condenser mic with a preamp connected to a analog pin would work so that once the sounds are loud enough and thus the analog pin reading higher, you can measure "loudness"

If you want to make it smart, you could possibly look for an experimentally determined ratio of frequencies that tend to indicate yelling. An FFT library, or more easily implemented, the MSGEQ7 chip, could monitor microphone input and generate a table of signal power within several frequency bands. For example, you might find that the furnace running will add some low frequency noise plus some across the board. Normal conversations might tend to lower frequencies. Yelling will probably range into the higher frequencies, and the peaks will probably be significantly more than the baseline average of the past few seconds.

You can make an electret mic amp based on circuit around the web, or use Sparkfun's electret breakout with amp. They have the MSGEQ7 as well, so that's handy.

That's the hard work...determining your output is the fun part. Maybe lots of bright LEDs that bathe the room in red? A photo of a frowning librarian that uses a servo to put a finger to their lips while a recording blasts "SHHHH" repeatedly? A bunch of USB missile launchers that pop up out of the furniture and send nerf darts flying everywhere in mutual assured destruction? A fog machine?