The currently available latest textbook that is a
companion to ENC software is "Engineering Noise Control" 6th edition by
D.A. Bies, C.H. Hansen, C.Q. Howard and K.L. Hansen.
For details of where to purchase this book as
well as details of where to purchase other books by Colin Hansen and his
co-authors please click on the Noise Control Textbooks section on the left hand
menu.