You want to set iTunes to import audiobook CDs quite differently than you would for importing music. You don’t need to use a high bitrate; that leads to huge files, with little improvement in quality. (But “see below”:#audiophile if you have particularly sensitive ears.)
You also shouldn’t need stereo, because most audio books are mono; saving the left and right tracks only doubles the file size, without improving the sound. Last, you want to make sure the files are bookmarkable on your iPod; AAC files have better support for audio bookmarks than MP3 files do. In particular, with tools that have become available for podcasting, you can save “chapter marks” in AAC files, which are very useful (especially on an iPhone); and there are other advantages of the AAC format, so that’s what I recommend.
h3. How to Configure iTunes with Optimal Import Settings for Audiobooks
These instructions are written for iTunes 7 (and are nearly identical for iTunes 5 and iTunes 6). For older versions of iTunes, see the “older instructions”:/audiobooks/itunes/old/.
# Launch iTunes, and open the Preferences dialog.
# Click on the Advanced preferences icon, and then on the Importing tab:
!/images/itunes/prefs-advanced-import.png(iTunes Preferences, Advanced Importing panel)!
# Set the On CD Insert action to Show CD (iTunes 7) or Show Songs (iTunes 5/6).
%(explanation)You don’t want to auto-import, because when you import an audiobook there are a couple of steps which are easier to do _before_ you import. If the import starts automatically, you’ll just have to cancel it.%
# In the Import Using pop-up, choose %(ui)AAC Encoder.%
%(explanation)This format provides higher quality and better support for audio bookmarks. It’s also the default setting.%
# In the Setting pop-up, choose %(ui)Spoken Podcast.%
# Uncheck %(ui)Play songs while importing.%
%(explanation)This option slows the import process tremendously.%
# Uncheck %(ui)Use error correction when reading Audio CDs.%
%(explanation)This *really* slows the import process…though it can help deal with dust or scratches on the disc, useful if you’re importing CDs from the public library, which are often seriously abused. But try it with this turned *off* first.%
# Check %(ui)Create file names with track number.%
%(explanation)This will add the track number to the file name, which helps keep things in order in the Finder or Windows File Manager.%
# Check %(ui)Automatically retrieve CD track names from Internet.%
%(explanation)This may auto-fill in some of your book’s metadata, though you have to be careful with audiobook information off the Internet.%
# Click %(ui)OK% to close the iTunes Preferences panel, and go back to importing your audiobook. (“Audio CDs”:/audiobooks/itunes/importing-audio-cds/ or “MP3 CDs”:/audiobooks/itunes/importing-mp3-cds/)
h3. Changing Your Settings Back for Music
Be sure you change your settings back before importing music CDs, or your music will sound terrible. If you’ve forgotten what your import settings were, just click the %(ui)Default Settings% button in the AAC Encoder dialog (above), to reset to the “High Quality” setting.
h3. If You Have “Audiophile” Ears
The import settings described above essentially mimic the audio quality which is provided by Audible.com’s highest quality (and largest) audio files. Those files are digitized in a single mono channel at 32 kbps with a 22 kHz sample rate. This is a huge step down from the quality of audio on standard Audio CDs.
For most people and most audiobooks, this drop in the overall level of quality will not be perceptible, at least not to distraction, because spoken word doesn’t need the same “resolution” as music to sound good. I’ve done listening tests in my quiet office, and while I’m sure there must be a difference, I can’t really hear it when the sound is strictly spoken voice.
But if you have very sensitive ears, or perhaps are hard of hearing, the drop in audio quality may be more apparent, to the point where it is irritating or grating. I have certainly heard that feedback from a small but non-trivial portion of readers. (I wish my hearing was that good!)
If you are blessed with such acute hearing, or if an audiobook has significant passages of music, audio effects, or stereo (perhaps in a book with multiple readers), you may want to import your audiobooks at a higher quality setting, and trade disk space for better sound.
What should those settings be? It depends on your ears. My recommended settings import audio in mono, at a bit rate of 32 kbps with a sample rate of 22 kHz. The Apple iTunes Music Store delivers music in stereo at a bit rate of 128 kbps and a sample rate of 44.1 kHz, which is not coincidentally the default import setting for iTunes and the AAC encoder.
If music from the iTMS sounds fine to you, then you could import with the default settings. Or you could experiment, splitting the difference in the bit rate, and see if it still sounds good to you. You can also choose to go with mono or stereo, depending on the audiobook (keeping in mind that mono AAC tracks seem to be able to crash an iPod on occasion). Mono tracks will normally be half the size of stereo tracks.
Unfortunately even in the Custom settings dialog, iTunes doesn’t give you direct control of the sample rate; you can only usefully choose 44.1 kHz, though the %(ui)Auto% setting will, combined with other settings, result in a 32.000 kHz sample rate, for reasons which are mysterious to me.
If you do decide to experiment, I would be very interested in hearing what settings you finally settle on, and some qualitative comments on the differences you hear.