Dog scratching door alert

I have 2 new puppies who are only 10 weeks old.

They like to scratch the door and glass to say where am I.

Well I am probes lay at work but maybe I just want them to stay out a little longer.

I was thinking it's would be interesting to make a small buzzer alert when they try to scratch the door.

SO they scratch and something is triggered, a light, or s piezo buzzer or a speaker.

I have some sound modules for arduino like this

But i don't wank to alert in any sound, but the sound of the scratch?

I assume the need some sort of frequency monitor but I am not sure where to start?

Is there any projects that do this already?

If not any pointers would b appreciated.

Chris

First of all, can you record and replay the scratching sound? Or make your puppies scratch on command?

Then you can use some FFT or similar frequency analysis program, to find out more about the specific sound characteristics to detect. Don't expect too much from (cheap) sound detection modules, they may not be selective enough to distinguish scratching from other noise, in detail in the low frequency range, You may have to develop your own filter module, in either hard- or software - can you?

A contact microphone, mounted on the door, may be the right input device.

As a different approach, why not teach your puppies to activate some sensor contact, perhaps two in sequence, to get some attention? With different (personalized) feedback depending on the activation count or sequence...

iisfaq: But i don't wank to alert in any sound, but the sound of the scratch?

Cat scratch fever?

What about fixing to the door a small hinged plate connected to a microswitch. If the dog gets a reward when he presses the switch (such as a friendly sound) he might stop scratching.

...R