From UESP:

"Not mentioned in the description for the third tier shout is that several shouts have their magnitudes and/or durations amplified by a factor ranging from 1.10x to 1.50x. This is applied via a hidden perk applied by the third word's shout cooldown-reducing effect."

Anyone have mor info on this?

Animal Allegiance: Magnitude * 1.25
Aura Whisper: Duration * 1.50
Become Ethereal: Duration * 1.50
Call of Valor: Duration * 1.50
Disarm: Magnitude * 1.25
Dismay: Magnitude * 1.25
Elemental Fury: Magnitude * 1.25
Fire Breath: Magnitude * 1.25
Frost Breath: Magnitude * 1.25
Ice Form: Duration * 1.25
Kyne's Peace: Magnitude * 1.25
Marked for Death: Magnitude * 1.25
Slow Time: Duration * 1.50