Audible moving to Enhanced Format ONLY

[CRussel]

In email today:

In the upcoming weeks, we will be moving all downloads to an enhanced, high-quality audio format and will no longer support format 4 downloading.

We’re excited about providing you with this higher-quality listening experience. Your Audible titles are yours to keep and will be available for download in the new, higher-quality audio format. If you prefer to listen to your Audible titles in format 4 audio, you will want to download them all to your device before we make the switch on 6/30/2020.

You can continue downloading using the Audible Manager software on your computer if you would like, but you will need to make sure you are downloading in Enhanced format. If you switch to a different computer in the future, you will need to download a new software called AudibleSync, which we are working on now.

Any of you using older devices that won't support Enhanced Format need to do a download before the end of June.

[Byrdie]

I have an iPod 6 -- I think. Got it at least 3 years, went on sale when the then-latest & greatest came out. Too old for this new format? If so I am NOT going to buy another one just for Audible when the one I have works just fine thanks. I have carefully backed up my purchases there but still have a freebie or two in need of liberation so I can play it when & where I want. Does anybody know if the new format is "de-crap-able"? Because if I can't safeguard future purchases I just won't shop at Audible and will stick to borrowing from the library even if they don't always have the books I want.

[CRussel]

The new format is actually much easier to liberate.

[odamizu]

nevermind

[stumped]

can someone explain, scientifically, what makes this audio " enhanced"
[ audible site is useless. its says new format is minimally compressed, old is slightly compressed - or vice versa - so they changed one adjective - pretty meaningless ]

enhanced often means digitally manipulated in various (bad from an audiophile perspective ) ways e.g. boost bass, add reverb effects, add spacializers or "crystal sound"

i don't get why /how a recording of someone reading out loud needs "enhancement"

or is it really just enhanced DRM buried within marketing hype.

surely, to actually "enhance" you just record using the same format at a higher bit rate
e.g. best mp3 is 320kbs, typical audiobook mp3 is 64 or less kbs

[Uncle Robin]

Originally Posted by stumped

can someone explain, scientifically, what makes this audio " enhanced"

The cynic in me assumed the "enhanced" bit was the DRM

[Quoth]

Originally Posted by stumped

can someone explain, scientifically, what makes this audio " enhanced"
[ audible site is useless. its says new format is minimally compressed, old is slightly compressed - or vice versa - so they changed one adjective - pretty meaningless ]

surely, to actually "enhance" you just record using the same format at a higher bit rate
e.g. best mp3 is 320kbs, typical audiobook mp3 is 64 or less kbs

Actually recordings are done lossless. The final stage of publishing before DRM addition sets the compression. Oddly some audio book distributors want 44.1k sampling, perhaps for CDs, which are lossless. MP3 is 48K sampling, purely to make input and output filters cheaper and it's a nice round number. The CD sample rate is more even than needed for quality, but was to make filters achievable and suit the data rate of helical scan tape machines for digital adapted from analogue video.The data rate is 44100 x 16 x <number of channels> and any error correction overhead, if any. Red Book CD Audio is 2 channels and almost no error correction. CD Data uses extra error correction.

If it means anything other than less compression it's madness.

[stumped]

i thought that one reason books has low bit rates, compared to music, is that you don't need to capture full frequency range, just the part that a human male, or female voice occupies. [ same principle applied to land line telephone design ]

then you can safely compress the hell out of it with mp3 or AAC because we know that only a few audiophiles/ recording engineers can distinguish good mp3 compression from lossless , and that they only do it by intensely focusing on esoteric stuff like how the sound of cymbals decays.
so no pair of golden ears is going to detect "slightly" vs "minimally" compressed spoken voice vs uncompressed

this had to be a mix of hardening DRM under some marketing spin about larger files sound better. [ its bigger so we charge you a lot more because y'know - quality - and you are too dumb to spot the scam ]

as another compare - do you happen you know how BBC go about broadcasting a radio play/ making that available on i-player?

[murraypaul]

A quick Google suggests that:
- Format 4 is fixed at 32kb/s, 22kHz, mono, while enhanced is more flexible, with 32-128kb/s, 22 or 44kHz, mono or stereo. (In practice seems to be 64kb/s, 22kHz)
- Enhanced is AAC, Format 4 is MP3
- Enhanced generally uses twice as much space.

Some detail here: https://audible.custhelp.com/app/ans...st-suits-me%3F

[shalym]

Originally Posted by murraypaul

A quick Google suggests that:
- Format 4 is fixed at 32kb/s, 22kHz, mono, while enhanced is more flexible, with 32-128kb/s, 22 or 44kHz, mono or stereo. (In practice seems to be 64kb/s, 22kHz)
- Enhanced is AAC, Format 4 is MP3
- Enhanced generally uses twice as much space.

Some detail here: https://audible.custhelp.com/app/ans...st-suits-me%3F

...and don't forget,

Originally Posted by CRussel

The new format is actually much easier to liberate.

Shari

[stumped]

Originally Posted by murraypaul

A quick Google suggests that:
- Format 4 is fixed at 32kb/s, 22kHz, mono,..

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

[pwalker8]

I've been using the enhanced for a number of years. The big difference is that the enhanced audio quality means that the file sizes are larger, thus taking longer to download and taking more space on your device. Looking back at my audiobook downloads, it's been out there for a pretty long time. It made a difference back in the days of 8 GB or less devices and every byte counted. I take this as just a move to removed an old, obsolete format. I expect sooner or later they are going to drop multi part files as well.

[Quoth]

So "slightly more compressed" means x2 to x4 compressed and more distortion than a cassette tape. The 32 kps will not have tape hiss. 22KHz sampling means less than 11 KHz response, which is about OK. But cassette tapes recorded with AC bias will have lower distortion, if AC Erase they'll have acceptable S/N (hiss) for speech and can manage 11 Khz.

Well, this is to be lauded. Obviously you need a way to store backups on a PC, or use a phone app and an SD card (32 G or 512 G depending on if HC or HX cards supported).

[fjtorres]

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.

[stumped]

i am pretty sure the old format was AAC in an audible DRM wrapper.

i doubt that would develop their own new format from scratch , so there are not a lot of contenders. MP3 is not really drmable, Microsoft have abandoned WMA, so there's AAC, OGG vorbis ( as used by spotify), what else? Not flac, because that's lossless not "slightly compressed"
i suspect they have just upped the AAC bit rate a little and maybe hardened the DRM,
variable bit rate for speech makes not much sense, complexity does not vary enough.