One of our Fire Repeaters has changed rx pl tones. I don't know what it is yet as they only use it paging one or two departments off the tower. I have a recording of the audio and I am trying to decode the PL tone from that recording, otherwise, i'll have to wait until they page off that new tower again and have my scanner handy.
Not too sure if an audio recording will give you the results you want.
There may be a high-pass filter somewhere in the mix that blocks
the low frequencies of a PL tone from being "heard" (recorded).
On another note:
Before I had a scanner that would decode PL's,
I used my digital multimeter which has a built in 2 KHz freq counter.
I simply placed the probes across the discriminator tap and ground.
The PL read out on the LCD display. Nice and easy.