Quote:
Originally Posted by stumped
aha - so that's what " slightly compressed" means. i dread to think what medium or heavy compression might mean in Audible Speak
1kbs if you are lucky 
"so i took your 1440Kbs wav / your lossless 700Kbs flac and slightly compressed it to 32kbs"
i was listening yesterday to a Spotify podcast - excellent quality - probably many many more bits than audible's new "enhanced" offering. in fact a quick google suggests that Spotify only accept 96 - 320Kbs podcast file submissions- so at least triple what audible will sell you |
Bit rate alone says nothing.
The encoding codec matters, too.
Back when music file size mattered, WMA's calling card was 32kpbs music that was equal or better than MP3 and 128Kbps that was better than MP3 320kbps.
They also had a voice codec that produced FM quality as low as 4kbps.
Moot point these days as lossless is easy to move and store.
The same applies to video: h.264 was great for reducing 25Gb mpegs to maneageable size (say 4-9GB) but h.265 produces smaller files of equal or better quality.
https://www.macxdvd.com/mac-dvd-vide...65-vs-h264.htm
So the first question about Audible's file change is which codec(s) they're using.
If it's the same, then bitrate may mean something.
Then there is the question of whether the encoder uses a fixed bit rate across the entire file or analyzes the audio sampled by chunks and applies a variable bit rate depending on the complexity.
(Unlikely for voice but not impossible.)
But if it isn't the same codec, the new one might be better at the same rate and much better at slightly better or even smaller rates.
In the old days, the goal was to make the files as small as possible for download, but these days the goal is more about quality and playback requirements. Audiobook files aren't terribly demanding compared to video or classical music but the files are loooonngg. So File size still matters given that a lot of playback is on phones.