When navigating the playback controls on either the Lock Screen or Notification Center, VoiceOver does not recognise or speak the total duration time which is visually present on screen below the timeline slider/scrubber; speaking only the current position of whatever audio you are playing.
1. Ensure that VoiceOver is enabled.
2. Open an audio app such as the Music app, and start playing audio.
3. Navigate to the Notification Center (or go to the Lock Screen).
The playback controls should be present on screen at this point.
4. Move VoiceOver focus through the playback controls until focus is on the timeline slider.
You would expect VoiceOver to speak something like ““Track position, 1 minute 30 seconds of 4 minutes 20 seconds.”
However, even though the current position and total duration of the current audio track are both visually present on screen, VoiceOver only speaks the current position. So, in the above example it would speak “Track position, 1 minute 30 seconds.”