Create New Sample, 44.1KHz stereo, 16-bit

Generate 15 sec mono white noise, max 'intensity' and level
Cut to Clipboard

Generate 15 sec tone
Frequency: 1500Hz, +/- 500Hz, (1 sec sweep) -22dB below maximum
Stereo Phase Differential: modulation=0Hz, phase variance=360 degrees (max)
Amplify: Fade Out

Mix noise from Clipboard: 80%

Append 3 seconds of gap
Repeat again using stereo white noise
Repeat all of the above for 1Hz, 10Hz, 100Hz SPD