Common sense would tell us that earth-moon-earth communications (EME or "moonbounce") would be extremely difficult on a frequency as low as the 7407.5 kHz seen here. Common sense would be correct, except when the transmitter is HAARP on full rock and roll with some number of gigawatts effective radiated power beaming right at the moon.
This record is of an earth-moon-earth test done from HAARP on January 20, 2008. This test consisted of a long series of CW dahs exactly two seconds long. There was a three-second pause between each dah, in order to listen for the long-delayed return from the moon.
On the left of this plot, we see just that. A long dah terminates at exactly 32:57 after the hour, and sure enough, there is the reflection, shifted a little lower in frequency. This happens again on the dah terminating at 33:02. After this, the reflections become hard to see, and probably inaudible on a speaker. Pretty interesting stuff.
Plot made with Spectrum Lab, as received in California.