I think the correct name for this version is the "International Sound Version"
It was the cheaper way of making versions for foreign non-English speaking markets as opposed to re-shooting the
film entirely with a different cast (e.g. the Spanish version of Dracula 1931)
Phantom of the Opera was re-released in Sound on Disk Versions ONLY in 1929. The domestic
version was a Part-Talkie and included Ballet Sequences in Technicolor. (An ad in Motion Picture News is worded in such a way as to suggest there was more than one ballet sequence in color)
The second version was the International Sound Version which unfortunately had these musical color sequences cut
as well as any talking sequences. Luckily the non-musical Technicolor sequence was kept intact.
(There was no new silent version)
I think a lot of confusion would be cleared about films of this era if people would keep in mind that film with
soundtracks are not silent.
A silent version of "All Quiet on the Western Front", if it ever existed, would have been cut down even more to
remove the musical interludes and portions that relied on sound effects ... Frankly I prefer the recorded Sychronized Scores of that period to any modern score, as I find the modern music to be extremely anachronistic and annoying.
If I watch a film that has no original Vitaphone score I simply turn the modern music off and play a random score recorded in that era.
They had very good taste in music in the 1920's and the scores relied heavily on popular music of the day and made heavy use of string instruments resulting in elegant and sophiscated sounding scores.
Modern scores have to rely on public domain music and and almost always played in a style that has nothing to do with the era the film was released. Of course I realize that a lot of people rely on making these silly scores to make a living and of course we can't forget the movie studios who always love to re-copyright a public domain film by adding a new score and therefore being able to copyright their "new version" The wonder is how they managed to trick so many people into believing their modern scores are better than the originals.
Case in point, the recent DVD release of a so called restoration of the "Iron Mask".. Even though a complete set of the Vitaphone disks was made available, the people responsible chose to add a new score and keep a bit of the dialogue sequence. Sorry but adding a new score does not result in a restoration. Audiences in 1929 saw or heard nothing of the kind. Of course the DVD producers are happy because if they had released the film with the original Vitaphone score they would of ended up releasing a public domain DVD as the original sound version of the "Iron Mask" is now in the public domain.