Star Trek TNG Ambient Engine Noise (Idling for 24 hrs)

Featuring an observant comment from Deconstructonator:

For those interested, if you listen carefully you hear that this is not only the´╗┐ engine sound from Enterprise NCC-1701-D, but with the characteristic frequency variation you hear at the 24-28 Hz range, prior to the warp core repairs and subsequent antideuterium stabilizer upgrades after Stardate 45156.1. You can hear this distinctively at 6:33:34 and 14:12:44.