The word "呼呼" is formed by duplicating the character "呼", which is a pictophonetic character consisting of the semantic radical "口" (mouth), indicating a relation to sound, and the phonetic component "乎" (hū), which suggests its pronunciation; this reduplication creates an onomatopoeic term that directly imitates sounds like wind blowing or snoring, emphasizing their repetitive or continuous quality through the doubled structure.