- Ludo Bagman used this spell when he was the announcer for the Quidditch World Cup in 1994, and again later that year during the Triwizard Tournament at Hogwarts School of Witchcraft and Wizardry.
- Albus Dumbledore used this spell a number of times during the Triwizard Tournament.
- In 1998, this spell was used by Lord Voldemort several times during the Battle of Hogwarts. He used it to powerfully extend his voice, spreading from a far distance to the school. It was as though Voldemort was standing next to the individuals that he was communicating with.
- Cornelius Fudge used this spell to amplify his voice and annouce the start of the 422nd Quidditch World Cup.
Sonorus is Latin, meaning "loud".
Behind the scenes
- In the film adaptation of Harry Potter and the Goblet of Fire, Minister of Magic Cornelius Fudge used the Sonorus Charm, as the character of Ludo Bagman did not appear in the film.
- In the film adaptation of Harry Potter and the Goblet of Fire, the caster was required to place the tip of their wand to their throat, although no such requirement was mentioned in the books.
- In the instances in which it was used in Harry Potter and the Goblet of Fire, Sonorus simply magnifies one's voice; however, when Voldemort used it in Harry Potter and the Deathly Hallows: Part 2, his voice would enter into someone's head and actually cause physical pain. This may be due to his intentions, or an entirely different spell. It is also interesting to note that it seemingly has no ill-effects on his Death Eaters.
- Harry Potter and the Philosopher's Stone (film) (First appearance)
- Harry Potter and the Goblet of Fire (First identified as Amplifying Charm)
- Harry Potter and the Goblet of Fire (film)
- Harry Potter and the Deathly Hallows
- Harry Potter and the Deathly Hallows: Part 2