The Hearing Amplifying Charm (Clarisonus) is a charm used to amplify one's hearing.
The Hearing Amplifying Charm is used to enhance the hearing of either the user, or another target. The spell gives the target the ability to hear things they would normally be unable to, amplifying the volume of sounds that would be below their hearing range, and extended their ability to hear from a distance. This spell is notably used by more elderly wizards whose senses begin to fail them, in the absence of the No-Maj "hearing aides".
Prolonged usage of this spell, however, can result in a lightheaded sensation.
The incantation comes from a Latin word, meaning "loud", can be be synonymous with "Sonorous", an incantation with a related effect.