Perhaps more relevant is another R-R book - "Aircraft Noise" by the late Mike Smith.
As this used to be my specialized subject, I'll offer a few more comments.
Even the very high bypass engines of late are still dominated by jet noise (i.e. exhaust mixing noise) at take off settings, but the fan noise isn't too far behind. The fan tips are typically at about 1.4 relative Mach number, so the shock waves from the tips propagate non-linearly to produce what is often called "buzz-saw" noise. Small differences in the fan, length of duct and acoustic lining of the duct can significantly alter the character of this noise. It is characterised as a set of tones at harmonics of the LP shaft frequency peaking in level at about 1 to 1.5 times the blade passing frequency (i.e. 1 - 2 KHz). Subsonically you only see harmonics of the blade passing frequency.
The jet noise is mainly characterised by the velocity of the hot exhaust and the diameter of the hot nozzle. Lots of techniques are used to encourage mixing with the surrounding bypass flow, especially with long cowl engines with buried hot nozzles.
I don't have much specific knowledge of the engines that you mention, but I hope this better explains it to you. Its a very big and expensive subject for the manufacturers.