Normally the AUDIO_TS folder will be empty and not contain any files.
I just checked and found that Tarzan II has English (Dolby Digital 5.1), English (DTS 5.1), and French (Dolby Digital 2.0).
Perhaps your audio problem might be related to DTS 5.1 Surround Sound. If you only include DTS Surround 5.1 Surround Sound audio stream in your backup copy and your playback device is does not support DTS Surround 5.1 Surround Sound you will not hear any audio in the play back.
Suggest copying Tarzan II again and only include the AC 3/6 audio stream in your backup copy.
Suggest viewing the below Forum posting for information on how to determine DVD audio streams. Refer to posting #6 comments.