Scientists have discoved conch shell musical instruments at a 3,000 year old pre-Inca site in Peru. The shells come from Strombus galeatus, a gastropod found in the Pacific Ocean. They are similar to 20 'pututus' found in 2001 at Chevin de Huantar in the Peruvian Andes. All are carved, polished and painted and have mouthpieces and V-shaped cuts. According to Perry Cook, a shell musician and computer scientist at Princeton University (US), the cuts may have been used to hold the instruments while they were played. The find was reported at the Second Pan-American/Iberian Meeting on acoustics in Cancun, Mexico.
     The shells may have provided the music for religious cermonies. The sound produced is very low-pitched and eerie. "You can really feel it in your chest," says Jonathan Abel, an acoustician at Stanford Universityís Center for Computer Research in Music and Acoustics. "It has a rough texture like a tonal animal roar." Researchers recorded the music from the shells and conducted a digital analysis. They emit only one or two tones but the pitch can be moderated by obstructing the opening. This is similar to the effect produced when a musician's hand is placed into the bell of a French horn.
     Recordings were also made inside the stone labyrinth which served as a ceremonial chamber. Because of the unique acoustics, the music echoed around the walls and, according to Abel, created a "sense of confusion". "Were they used to scare people while they were there?" asks Abel. "There are still a lot of things left open."
     Psychoacoustics studies the effect of sounds on behavior. It was in modern settings and at ancient sites. "What your ear can actually hear plays into how you would behave, or the psychological experience in the situation," says Abel.
     The conch shell instruments can be heard here.
     
Edited from ScienceNews (18 November 2010)