Squawk may pertain to the loud sound or shrill made by patient with a lung disorder or by a bird when alarmed. The squawks produced by patients with lung disorder (e.g. hypersensitivity pneumonitis) are characterized by short wheezes or squeaks. They demonstrate waveforms in sinusoidal pattern. The frequency ranges from 200 to 800 Hz and the duration, from 10 to 100 ms. In birds, the squawk refers to Nyctanassa violacea, commonly known as the yellow-crowned night heron. It belongs to the family Ardeidae of the order Pelecaniformes, class Aves, phylum Chordata. This bird species is known for its squawks as one of its vocalizations. It is heard when the bird lifts off or it gives an alarm or aggression call.
- Paciej, R., Vyshedskiy, A., Bana, D., & Murphy, R. (2004). Squawks in pneumonia. Thorax 59:177–179.
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