The hakgediya is a type of conch shell (the shell of a large marine gastropod mollusk) which is used as a kind of trumpet in the traditional ritualistic music and religious folk art-music of Sri Lanka,[1] which has been somewhat influenced by Indian music.
The hakgediya is not used to perform melodic variation or to be the main instrument in the ritualistic pice.
The variance found in the notes emitted by the hakgediya is in dynamic range (volume), as the player can choose to blow soft or loud, with a sharp or smooth attack, sustain, decay and release.
[3] In traditional Buddhist art music rituals, the main instruments are the drums pertaining to the Avanaddha category, the hakgediya is more of an accompaniment.
The hakgediya is used in the ritual in honor of the Triple Gem (Buddha, Dharma, Sangha), right after chanting the Astakas, Sahali, and Curnikas which ensures blessings to all Gods.