Err… WWVB has no audio range. The carrier frequency is only 60 kHz. It’s effectively a CW signal since the amplitude is only modulated once per second.
There is an audible setting in the app that shifts the signal down to human range.
> WWVB has no audio range
I got my WWVB and WWVH confused!
There's a reasonable emulator here: https://wwv.mcodes.org/
Unfortunately it doesn't let you play both at the same time, which is what you need for the full experience.
There’s a voice mode station that mixes time signals and voice messages together during broadcast. This station also includes GPS errata from time to time, which in my head canon, are received by solo sailors crossing the Atlantic.
I thought this was Boulder, but I assume not?