The Halldorophone, an electro-acoustic string instrument resembling a cello, generates sounds through the use of feedback

Halldór Úlfarsson is the inventor behind the Halldorophone, an instrument resembling a cello but distinguished by its electro-acoustic capabilities, which produce rich sounds through feedback. This occurs as the instrument’s sound is captured by a microphone or pickup, amplified, and then fed back into the instrument, creating a continuous loop. The sounds generated are a result of the vibration of its strings, which are then further shaped or altered by an electronic component attached to the instrument.

The concept behind the Halldorophone’s design is to harness feedback deliberately, a choice made by Úlfarsson in his dual role as artist and designer. He took his innovative creation to Sónar+D 2024, accompanied by his team from the Intelligent Instruments Lab. There, attendees had the opportunity to experience the Halldorophone firsthand. Many were amused to discover that despite its cello-like appearance, the instrument they were playing was something entirely different, highlighting the unique nature of Úlfarsson’s creation.

In the case of the Halldorophone, the instrument employs a pickup system. Halldór Úlfarsson outfits this unique musical device with four distinct strings. The primary strings, positioned directly on the instrument’s body, are the ones the musician engages with directly. The remaining strings are known as ‘sympathetic’ strings, which resonate independently as the main strings are played. Each string is equipped with its own pickup, functioning similarly to a microphone.

This mechanism captures the sounds produced by the strings, which are then amplified. The amplified sound is emitted through a built-in speaker, specific to this cello-like, electro-acoustic string instrument. The sound from the speaker, in turn, causes the strings to vibrate anew, initiating a feedback loop. This loop continuously cycles the sound through the strings, pickups, amplifier, and speaker, creating a rich auditory experience.