Chrome Version: 58.0.3004.0 (Official Build) canary(64-bit)
OS: Win10
Screen reader: NVDA 2016.4 and JAWS 18

P3 stated: “UI when installing extensions has a lot of unknowns. While you’re installing, the installation progress you hear “unknown” a lot.” 

What steps will reproduce the problem?
(1) Using above combo
(2) Install *any* extension
(3) Note progress

What is the expected result?
NVDA progress earcons that rise in pitch/3D-audio or percentage

What happens instead?
lots of unknowns are uttered