Is there any way to include the “Export Multiple” function (splitting the file into multiple files based upon labels) within a chain?
I am hoping there might be some way to automate this, because it is the one part of my process that I have to do by hand each time.
No, Export Multiple is not supported by Chains, but if you tell us what you are trying to do and your current working method, we may be able to suggest an alternative.
Thank you Steve.
I am converting audiobook MP3 files to make them more suitable for MP3 player I use while swimming, which has no screen and an awkward user interface via just a few buttons.
My existing chain uses TruncateSilence, Amplify, ChangeTempo (to increase the speed by about 50%) and ExportMP3.
I then open the resulting file in Audacity and manually use Regular Interval Labels and Export Multiple to break the file into 3-minute chunks. I do this because sometimes, when trying to increase the volume on my MP3 player, I accidentally jump to the next file. If the files are an hour long, jumping back usually means I have to listen to a lot of stuff I’ve already heard. 3-minutes increments are a lot less frustrating 
For anyone interested in listening while swimming, I use the Exeze Rider Waterproof MP3 Player 4GB, which I bought for £30 on Amazon UK. Despite the limitations of the interface, I have found it a lot better than the Sony Walkman W273 4GB Waterproof MP3 Player I was using before. I usually swim laps for around 90 minutes every day, so, being able to listen to audiobooks at the same time is a sort of miracle, and so is Audacity.
Your current method sounds pretty good, but a couple of points:
It probably does not matter too much for your use case, but MP3 format (and any other form of “lossy compression”), discards some of the audio information during the encoding process so as to reduce the file size. This causes a loss of sound quality that can never be recovered. The effect is cumulative, so each time the audio is encoded, a bit more sound quality is lost.
As you are exporting as an interim step, it would be better in terms of sound quality, to export in a “lossless” format such as WAV. As you will then only be encoding to MP3 once (at the end of the process), you will cut out one “lossy” step. The final MP3 encoding will still lose a bit of sound quality, but you will only be losing sound quality once, not twice.
How many files can your MP3 player handle?
Could you export the entire book as a series of (numbered) 3 minute files?
Does your MP3 player support “play lists”? If so, then you can “tie together” all of the files with a play list. In effect, this gives you one “file” for the entire book (the play list), and lots of short “chapters” (the individual 3 minute files).
Thanks Steve, your lossless tip is great, I would never have thought of that, I have now replaced ExportMP3 with ExportWAV in my chain, so that the final MP3 files will be less degraded.
So far, the most I have had on it has been a hundred or so files, but with a fairly big 4GB of storage, I presume that its firmware has been designed to handle a large number of files.
Most unabridged audio books are around 9 hours long and, on torrent sites, generally come in MP3 format, broken into chapters or sections, already numbered, and I append audacity’s numbering when I break up those files into 3 minute chunks. That keeps everything in the right order when I transfer them to the MP3 player.
Example: The 4-Hour Workweek-Part03.mp3 is one of 13 files I download, I split them into 3-minute files such as The 4-Hour Workweek-Part03-08.mp3
No playlist support, it simply treats all the files as one big alphabetical list, which works well enough when using the above naming system. The player is also seems to be reliable in remembering where I last stopped.