I cannot find any way to set the bitrate mode and quality for the sounds created using the Export to Multiple function, so I suspect that this would be a new feature.
I am recording small sound bytes of the pronunciation of words, phrases and sentences. About 1,000 at a time and have Labelled each of these.
To export these as distinct sound bytes I use the Export to Multiple function which has some interesting anomalies. The first is that I have to enter OK for EACH sound byte. i.e. there is no function to accept the metadata settings for ALL the sound bytes.
The second, more pressing issue, is that I cannot set the bit rate for the sound bytes. I have to put these through a post production process using an MP3 compressor to reduce the quality and size.
Metadata handling is a bit limited in Audacity and sometimes it is best to use a dedicated metadata editor after you have exported (such as MP3Tag), however there are some useful facilities available in Audacity that may be sufficient.
Go to “Edit > Preferences > Import/Export” and disable the option to “Show metadata editor prior to export step”.
Then, before you start the export:
Open the Metadata Editor via the File menu and enter all metadata that is relevant to all files (note that standards vary from one media player to another, so you will need to do some tests to see which data items are read by your player for the file format that you wish to use, and which ones aren’t).
You can now run Export or Export Multiple without the metadata editor opening. Only the data that you entered prior to Exporting is written into the exported files.