MP3 sampling rate...two things to think about here...MP3 is a compressed format designed for audio, i.e. speech and music. NBTV is most certainly neither of those. So the compression algorithm will 'throw away' information that we will not hear being missing in true audio but may be essential in NBTV video. Record NBTV in (say) WAV format and then MP3 and compare the difference both visually on a screen and on a 'scope.
The other thing is crosstalk between the channels. For stereo audio (speech, music) MP3 and the like 'blends' the lower frequencies into effectively a mono channel as in most listening arrangements it's hard to determine the source (left or right) of the lower frequencies, that's a natural human thing. Determining sound directionality is based on the speed of sound (around 305m/s) and the distance between our ears, then the brain can get a measurement of phase difference and determines the direction of the source. It does get quite a bit more interesting determining whether it's behind us or in front.
For NBTV that's a problem. MP3 may work well in certain circumstances and with suitable source material, but these days file size really isn't a problem, at least within the NBTV context. So really is there a reason to use MP3 or similar?
Klaas Robers covered this many years ago in a newsletter...
An alternative is FLAC, a compressed audio format. It doesn't achieve the same amount of compression, granted, but there's no crosstalk. It is also lossless, akin to Winzip...which is a viable alternative if you really need to shrink file sizes these days....
https://en.wikipedia.org/wiki/FLACSteve A.