n. Voice, the power of the Voice; Dragon Shout

Sahrot Thu'um, med aan tuz, vey zeim hokoron pah, ol fin Dovahkiin komeyt ok rein!
Mighty Thu'um, like a blade, cut through enemies all, as the Dragonborn issued his roar!
(Book, Songs of Skyrim)

Nords consider themselves to be the children of the sky, and the breath and the voice of a Nord is his vital essence. Through the use of the Voice, the vital power of a Nord can be articulated into a thu'um, or shout. Shouts can be used to sharpen blades or to strike enemies at a distance. Masters of the Voice are known as Tongues, and their power is legendary. They can call to specific people over hundreds of miles, and can move by casting a shout, appearing where it lands. The most powerful Tongues cannot speak without causing destruction. They must go gagged, and communicate through a sign language and through scribing runes.
(Book, Pocket Guide to the Empire, 1st Edition/Skyrim)

The Way of the Voice is an ancient, spiritual form of magic in which you project your vital essence into a “thu’um” or Shout.
(Ulfric Stormcloak, 000BFC4A)

But there are many Words of Power in Skyrim, carved in the Dragon tongue. Even from here, we can feel the Thu'um resonate from them.
(Arngeir, 000E76DA)

I cannot tell you in detail. I never heard [Dragonrend] used. ... It was the first Thu'um created solely by mortals.
(Paarthurnax, 0003FA43   )

Many of the dovahhe are now scattered across Keizaal. Without Alduin's lordship, they may yet bow to the vahzen... rightness of my Thu'um.
(Paarthurnax, 0009E073)

Thu'um se Dovahkiin inhus, Miraak. Hin suleyksejun oblaan.
The Dragonborn's Voice has the mastery, Miraak. Your dominion is ended.
(Sahrotaar, 0202BC55)

Thu'umii los nahlot.
His Voice is silenced.
(Dragon, 0009E072)

Naal Thu'umu, mu ofan nii nu, Dovahkiin, naal suleyk do Kaan, naal suleyk do Shor, ahrk naal suleyk do Atmorasewuth.
By our Voice we give it now (to you), Dragonborn, by (the) power of Kyne, by the power of Shor, and by the power of Atmora-of-old.
(Greybeards, 000C43A7)

The vital essence of breath and wind (su’um) projected into a Shout. Refers to individual Shouts and the general power of the Voice. Latent within Nords and within the Words of Power that power it. Associated with strength, power, the right to rule.

Related to su’um ‘breath/inner spirit’. If “Storm Voice’ is to be taken as a translation, may relate to an unattested word thu ‘storm/thunder’, meaning ‘inner storm/power’.

Also referred to as the ‘Storm Voice’ by the Nords.