For those looking to hear what this sounds like without buying any radio gear, there are many public kiwisdr sites that can hear 60khz. It's a matter of choosing AM decoding and tuning to the particular frequency.
Many of these have user limits and time limits as well. Note that you can also hear WWVB on 2.5mhz, 5mhz, 10mhz, and 15mhz.