I am currently working on a project with an Arduino. The final goal is to be able to detect different sound signals: A smoke detector sound and the sound of a doorbell. So I also have to differentiate between those.
For a first prototype we used the Sound Sensor module in order to recognize a loud sound by defining a certain dB threshold.
Do you think it is possible to detect different kinds of sounds with this sensor module as well (door bell and smoke detector)? Or does someone have any idea which sensors we could use to do that?
It doens't have to work perfectly, but I would like to show it somehow in a prototype.
quote: "Do you think it is possible to detect different kinds of sounds with this sensor module as well (door bell and smoke detector)?"
If you can write a description of each of the sounds so we can identify that sound and then tell us how to determine which one you are hearing, then it might be possible.
jremington:
What sorts and levels of background noise are present?
What percentage of false positives and negatives will be allowed?
The background noise doesn't have to be considered a lot in the beginning.
For a first prototype we just want to make it work in a silent room - we would like to play the 2 sounds on a speaker which can be directly next to the sensor. So in this case, we would like to be able to differentiate between both sounds.
Since none of us knows what your doorbell or smoke alarm sound like it's difficult to answer. How do you plan to tell them apart? For example if one is a continuous buzzer but the other beeps once a second it's pretty easy. Or if the doorbell plays Westminster Chimes and the smoke alarm sounds for 5 seconds then stops for 1 second over and over then no problem.
slipstick:
Since none of us knows what your doorbell or smoke alarm sound like it's difficult to answer. How do you plan to tell them apart? For example if one is a continuous buzzer but the other beeps once a second it's pretty easy. Or if the doorbell plays Westminster Chimes and the smoke alarm sounds for 5 seconds then stops for 1 second over and over then no problem.
So what are the two sounds like?
Steve
It doesn't really matter which exact sounds we are going to take. We just have to show that it is generally possible to differentiate between one smoke alarm sound and one doorbell sound.
So we could indeed modify those, so that it is easier to detect them.
Doorbell could be this:
Smoke detector could be like this.
So we can specify the sound - it just has to be one of each kind.
The easiest thing would be to use this sound sensor (not sure if it is possible with it though).
You STILL have not articulated the aspects of the sounds that makes them different. Once you can do that, you may be able to find outputs of a sensor that can find a correspondence between it's output and the two sounds.
It doesn't really matter which exact sounds we are going to take. We just have to show that it is generally possible to differentiate between one smoke alarm sound and one doorbell sound.
What you propose is basically On Off Keying (OOK) so you could simply measure the average amplitude of sound coming in, subtract the background, and check for those specific on/off timing patterns.
