kyu ru ru

rings and rings, whistling, ringing [high toned piercing sound, like a flute or an opera singer) (undulating high sound) [IW]

rings and rings, whistling, ringing * sounds of insects and small birds [IW]

laughing, songs rings and rings (high-toned piercing sound) [JV]

humming and chanting; to echo eerily; rings and rings, twittering; high toned piercing sound (like a flute or an opera singer), whistling, ringing [undulating high sound] [RY]

humming and chanting; (to) echo eerily [RB]

ringing and humming (onomatopoetic term for resonant tones, often of high pitch, such as singing or insect buzzing) [Erick Tsiknopoulos]