Low Latency audio
From Zenitel Wiki
In certain situations high latency on audio
Latency refers to the delay between when an audio signal enters a system and when it emerges. Excessive audio latency has the potential to degrade call quality.
PA-Announcement
Target goal: < 70 ms
For a typical use-case doing PA-Announcement operator do not like to hear himself with a long delay. Also we can have mixed analogue/digital systems where for example the main speakers are on dialogue path while audio is also placed on digital endpoints. The analogue path will be close to zero delay so audio in digital endpoint can not be large in zones where both audio sources is audible.