Double harmonic scale with quarter tones. Created by Hyacinth (talk) 07:11, 10 March 2010 using Sibelius 5. MIDI pitch bend appears to match intervals.
A sound stimuli to demonstrate combination tone from speakers. You should hear additional frequency of 500 hz. The sound itself is summation of1000 hz and 1500 hz.
This is a modified version of "earthkiller background 1", the background noise inside a space station. I removed some upper midrange (1700 hz) to make it easier to mix with dialog.
I used audacity with an internal mic to record this. Its good quality though. i just dialed some numbers on my house phone with the dialtone at the beginning. Its very clear there might be some background noise though.