sound recognition sensor?

Hi, i just need to ask.. as to what type of sensor is capable of distinguishing these two sounds..

video: sound test - YouTube

see, the corner of the floor tiles is producing a sound different from whats in the middle is producing, everytime i tap it.. like in the corner(tik,tik,tik)... middle (tok,tok,tok)..

the one with the "tok tok tok" sounds differently because it seems to have a hollow concrete/adhesive underneath..

say the output would be.. LED be logic 1 everytime the tok tok tok sound is recognized by the sensor..

my local electronics supplier suggested I buy this: Electret Microphone Amplifier - MAX4466 with Adjustable Gain : ID 1063 : $6.95 : Adafruit Industries, Unique & fun DIY electronics and kits
and also a piezo ceramic disc: https://i.ebayimg.com/images/g/0bEAAOSwR5VZk6kI/s-l225.jpg

Will this be enough though? are there any studies related to this?

also, I might stay away from using the piezo since i will be attaching a servo motor on a 4wd, and let the servo(attached with stick.. with ball bearing.. etc.) do the tapping.. if piezo is used, im afraid it will be dragged everytime the 4wd moves..

sorry for the english...

Get a proper microphone to record the sounds, and a processor of the caliber Raspberry Pi to do the sound analyses. An Arduino can't do this, not enough memory to store the sounds to analyse, not enough processing power to figure out which of the two it is.

The sensor in this case is not going to be the key element, most microphones that work fine in this sound range will work (piezo buzzers are usually cut resonate only at an specific frequency...) , but you need to use some FFT analisys for the sampled sound, that's going to be the way to find out the main frequency contained in the sound samples. After a lot of trial and error you will find out what's the frequency of the failing tiles, and the frequency of the OK tiles, so you can set a threshold level to let the Arduino find out for you.

Look up "arduino FFT" or check this guy's previous work on detecting frequencies:

edugimeno:
The sensor in this case is not going to be the key element, most microphones that work fine in this sound range will work (piezo buzzers are usually cut resonate only at an specific frequency...) , but you need to use some FFT analisys for the sampled sound, that's going to be the way to find out the main frequency contained in the sound samples. After a lot of trial and error you will find out what's the frequency of the failing tiles, and the frequency of the OK tiles, so you can set a threshold level to let the Arduino find out for you.

Look up "arduino FFT" or check this guy's previous work on detecting frequencies:
Holding Focus: November 2010

Thanks for the information. as for the analysis. would it be more easier to use teensy for this?(will buy if so) or the difficulty is same in arduino(already have one).

found this: Spectrogram Tool | FFT: Fun with Fourier Transforms | Adafruit Learning System

my concern is that the threshold difference might be very small for my project.(or this wont be a problem?)

mine is different from tone detection linked above.

FFT is highly maths intensive, so a faster processor such as the Teensy (or ESP32 maybe - don't know if there are FFT libraries for that one) with it's greater clock speed and memory will have a great advantage.

wvmarle:
FFT is highly maths intensive, so a faster processor such as the Teensy (or ESP32 maybe - don't know if there are FFT libraries for that one) with it's greater clock speed and memory will have a great advantage.

thanks! i might lean on a teensy as the pi is a whole new world to explore.