Extendable Ear

• Type: Magical Device, Eavesdropping implement
• Owners: Fred Weasley, George Weasley, Harry Potter, Ron Weasley, Hermione Granger
• Maker: Fred Weasley and George Weasley

An Extendable Ear is a magical listening device that appears as a long, thin, flesh-coloured piece of string. One end of the string is inserted into the user's ear, while the other, the “ear” end, is positioned near the source of the sound to be overheard, such as by being slipped under a door. The device functions as a magical form of ear-trumpet, channelling sound directly to the listener with remarkable clarity.

The primary function of an Extendable Ear is to allow a user to eavesdrop on conversations from a distance and through solid barriers like wooden doors. The sound travels magically along the length of the string to the listener's ear.

• Limitations:
  • The effectiveness of an Extendable Ear can be nullified by certain defensive spells. Molly Weasley successfully blocked one by casting an Imperturbable Charm on a kitchen door, which prevented the Extendable Ear from penetrating its magical barrier.
  • Physical interference can also disrupt its use. Hermione Granger's cat, Crookshanks, famously treated the end of an Extendable Ear as a toy, batting it away from a door and rendering it useless.

The Extendable Ear is an original invention of Fred Weasley and George Weasley. It was one of the first products developed for their joke shop enterprise, Weasleys' Wizard Wheezes, created during the summer of 1995. They funded their research and development using the one-thousand Galleon prize money that Harry Potter had given them from his Triwizard Tournament winnings.

The Extendable Ear plays a recurring role as an important tool for gathering intelligence throughout the series.

• In Harry Potter and the Order of the Phoenix, Fred Weasley, George Weasley, Ron Weasley, Hermione Granger, and Ginny Weasley use Extendable Ears to spy on Order of the Phoenix meetings at 12 Grimmauld Place. They manage to learn key details about Voldemort's plans before being thwarted by their mother.
• In Harry Potter and the Half-Blood Prince, Harry Potter uses an Extendable Ear to listen to a suspicious conversation between Draco Malfoy and Mr Borgin in Borgin and Burkes. This event solidifies Harry's belief that Malfoy has become a Death Eater and is involved in a dark plot.
• In Harry Potter and the Deathly Hallows, the Extendable Ear proves to be a vital survival tool for Harry, Ron, and Hermione while they are on the run. They use it to monitor their surroundings for danger. Most significantly, they use it to overhear a conversation between Ted Tonks, Dirk Cresswell, Dean Thomas, and the goblins Gornuk and Griphook. From this, they learn that the Sword of Gryffindor at Hogwarts is a fake and that the real one was moved to a Lestrange vault at Gringotts, a piece of information crucial to their hunt for Horcruxes. They also learn about the Taboo curse placed on Voldemort's name.

• The Extendable Ear is a magical enhancement of the real-world acoustic device known as an ear-trumpet, which was historically used as a hearing aid.
• In the film adaptation of Harry Potter and the Order of the Phoenix, the Extendable Ears are visually depicted much as they are described in the novel, appearing as long, flesh-coloured cords used by the Weasley children to eavesdrop on the Order of the Phoenix. (film)