Just FYI, PS Engineering
invented the "IRS" or
Intercom
Recording
System in
1992. It was originally part of our stand-alone digital intercom called flightmate(R)
http://www.ps-engineering.com/docs/Flightmate_DS.pdf
While way ahead of its time it was expensive ($2795), so it wasn't our most successful product. But it did bring portable digital technology into the cockpit. Not only did it have our "set it forget it" VOX intercom, but it also had a display that would show what Com and message number you were hearing. It was our first experience with Digital Signal Processing, but not our last.
The PMA450 series does that same thing, only better! When you are listening to a playback, the PMA450 series displays on the OLED graphics display, the Com and message number you are hearing. To the best of my knowledge, it is still the only audio panel that has this capability. You can also,
in real-time, change the volume of the playback using the audio panel's volume control.
Our new IRS is really smart too. If you're listening to a playback and ATC chimes in, it stops but when you press the play button again (either yoke mounted or front panel) it will repeat that message. You can go back into a total of 8 recordings by pressing and holding the play button, so you can get the message you want to hear.
Finally, if you are currently hearing something that you know you want to playback immediately, press the play button while ATC is live and when ATC goes off the air, that message will instantly play-back again.
I'm really proud of what our team has been able to provide GA pilots for their audio control. And to think it all started in 1983 when I bought an AA-1A that needed an intercom!