29Dec2015 23:36:18 Z
The left sound channel is horizontal acceleration. The right: vertical. The video shows the vertical and horizontal axes correctly.
The video runs at 10 times real time speed.
This is a magnitude 4.7, 22km deep, earthquake, 20 km west of Pongaroa
It was recorded about 82.3km distant in Kapiti, New Zealand.
The S wave arrives about 10.5 seconds after the P wave.
82.3km / 10.5 seconds = 7.8km per second of PS difference.
Turn it up.