Stereo sounds have issues.

[ZephaniahNoah]

The audio engine minecraft uses is kind of weird. If your .ogg files aren't mono then they won't play directionally. For example, the rooststalker sounds play at the same volume level in both ears at any distance. Turning so that the dragon is to your left won't play the sound in the left ear. It plays in both. This resourcepack fixes it. All I did was merge the audio channels into one.
https://youtu.be/20TDlZqUGXw

[GundunUkan]

Known issue, planned to be fixed next update. Most newer dragons have mono sounds but the older ones are from a time when I had 0 clue how to use Audacity lol

[MWall541]

Reopening; currently isn't fixed.