I have to calculate the periodicity of a audio signal like this: You can see by eye, that the volume rises the highest every second "blob". The spectogram (that is visualized logarithmically) shows this periodicity quite good.
Should I use the fast fourier transform to do the auto correlation with the frequency? Is there any preprocessing that is important with audio signals? I'm fairly new to audio processing and data science in general.
My second thought was to use a convolutional neural network and use the volume and frequency to train the model. But that requires more training data to configure the system.