Machine learning in audio?

I think that resources about speech processing would be a good introduction to audio files manipulation for machine learning in general.

For a broader introduction to audio, Machine Learning for Audio, Image and Video Analysis: Theory and Applications, Reviews Book by Alessandro Vinciarelli and Francesco Camastra could be a good read.

Also, check out some blogs like this one: https://www.analyticsvidhya.com/blog/2018/01/10-audio-processing-projects-applications/ (as you mention deep learning in the tags) that can give a good introduction with some hands-on experience.

Using Deep learning in audio processing is a very interesting field of study and there are not a large number of companies actually working on this problem set, so finding the relevant material is a little hard for this. But if you want to refer to the development and understand the thinking behind processing audio in images, refer to these links:

• Looking to Listen: Audio-Visual Speech Separation
• Representations of Sound in Deep Learning of Audio Features from Music
• Unsupervised feature learning for audio classification

For general sound, I recommend Computational Analysis of Sound Scenes and Events. Music and speech are popular sub-fields of audio that have a lot of literature dedicated to them, even before machine learning became a thing.

There is now a youtube channel dedicated to Audio Machine Learning, The Sound of AI. There is also an associated Slack community for discussions.