Write a Program Which Recognizes a Sound and Performs Action

Question

I would like to write a program which is capable of storing a sound pattern, such as a train whistle, horn (beep beep)...listening for the sound via the microphone...and the

Answer 1

Most algorithms I know of use the spectrogram (i.e. the spectum vs. time) for distinguishing sounds. How hard this problem will be can be estimated by how different your spectrograms look.

An aspect of your sounds that might make them easier to distinguish from speech is that they will likely have clear harmonic structure (i.e. look more like the violin than the voice in the wikipedia link). This harmonic structure can be super useful in distinguishing sounds, and could be helpful in your problem. This brings to mind another place to look: there's a lot of work in distinguishing bird songs, which have clear harmonic structure, and many published algorithms, though I don't know of free software that can be extended to your needs. Still, it might be useful to use birdsong analysis software to just take a look at your sound files. See the Raven project, for example, though there are many other free spectrogram packages.