@RexRed,
For me it was also chanting, which has nothing to do with birds.
Chanting is used in almost every religion and other areas of life
Some examples include chant in African and Native American cultures, Gregorian chant, Vedic chant, Jewish liturgical music (chazzanut), Qur'an reading, Baha'i chants, various Buddhist chants, various mantras, and the chanting of psalms and prayers especially in Roman Catholic, Eastern Orthodox, Lutheran and Anglican churches.
Chant practices vary. Tibetan Buddhist chant involves throat singing, where multiple pitches are produced by each performer. The concept of chanting mantras is of particular significance in many Hindu traditions and other closely related Dharmic Religions. For example, the Hare Krishna movement is based especially on the chanting of Sanskrit Names of God. Japanese Shigin , or 'chanted poetry', mirrors Zen Buddhist principles and is sung from the Dan tien (or lower abdomen) — the locus of power in Eastern traditions.