Tibetan horn

The Tibetan horn (dungchen; Tibetan: དུང་ཆེན།, Wylie: dung chen, ZYPY: tungqên; mongol : Hiidiin buree ; Chinese: 法号; literally: "dharma trumpet") is a long trumpet or horn used in Tibetan Buddhist and Mongolian buddhist ceremonies. It is the most widely used instrument in Tibetan Buddhist culture. It is often played in pairs or multiples, and the sound is compared to the singing of elephants. Tsultrim Allione described the sound:

It is a long, deep, whirring, haunting wail that takes you out somewhere beyond the highest Himalaya peaks and at the same time back into your mother's womb.

...
Wikipedia