Really good reference; very thorough treatment in 40 pages:

Kent, R. D., J. Dembowski and N. J. Lass (1996) The Acoustic Characteristics of American English. Chapter 5 (pp. 185-225) of N. J. Lass, ed. Principles of Experimental Phonetics. Mosby. You can get this book used for about £15‒£20. [Currently available online via SOLO from Hathi Trust during lockdown, but this may change later.]

Books perhaps worth buying one of:

Johnson, K. (1997) Acoustic and Auditory Phonetics. Blackwell. [Available online via SOLO]

Ladefoged, P. (2001) Vowels and Consonants: an introduction to the sounds of languages. Blackwell. [Currently available online via SOLO from Hathi Trust during lockdown, but this may change later.]

Fry, D. B. (1979) The Physics of Speech. Cambridge University Press. Rather dated but worth picking up second hand if you find a cheap copy (about £6 online); there are quite a few copies in college libraries. [Currently available online via SOLO, until May 30th 2021.]

Other readings

Ladefoged, P. (1962) Elements of Acoustic Phonetics. University of Chicago Press. [Currently available online via SOLO from Hathi Trust during lockdown, but this may change later.]

For a much more detailed, but much more expensive and less easily digested reference to acoustic patterns in speech, there's also:

Olive, J.P., A. Greenwood and J. Coleman [yes, me] (1993) Acoustics of American English Speech. Springer-Verlag, NY. £15 is a good second-hand price. Don't pay £160 for a new one ‒ we don't need the royalties. Unless you are royalty, in which case please buy copies for the whole family. As far as I am aware it is not available electronically, not even on piracy sites :-) Even I don't have an electronic copy, I'm afraid. So I can but recommend Kent, Dembowski, and Lass (reference above) for doing a great job in many fewer pages.