It might be out of memory error.
"MATLAB® can run out of memory if the result of the gather calculation is too large."
In this example, when I placed a break point after gather command, 7.4GB memory is occupied by MATLAB. 6.6 GB is used for MATLAB desktop process and other memories are used by Parallel workers.
So, 8GB RAM is not enough for executing this example.
I think there are two solutions.
- Try it on another machine which has more RAM.
- Reduce the audio files which were unzipped in tempdir\commonvoice (in Windows, it would be C:\Users\USERNAME\AppData\Local\Temp\commonvoice).