Comment by anyfoo

And not just for audio. In fact, I don't care about audio that much, and they're still some of my most treasured technical books (I have them in print form, and still reference them online pretty regularly).

Those changed my life, in a sense. Not my professional life, but outside of work it led me down a deep rabbit hole into mathematics, digital signal processing, and even analogue electronics and some light RF engineering. (This is not relevant to my professional life, since I started to take great care not to make any more of my hobbies my job.)

I spent endless hours thinking about this stuff on my commute, and hunched over Matlab.

The other book I recommend is Richard G. Lyons "Understanding Digital Signal Processing".