The word 嘶叫 is formed by combining two phono-semantic characters: 嘶 uses the radical 口 (mouth) for meaning related to sound and 斯 (sī) for pronunciation, while 叫 similarly uses 口 for meaning and 丩 (jiū) for pronunciation; together they create a compound meaning to scream or shriek, with both characters emphasizing vocalization through their shared mouth radical.