The word "呵呵" is formed through the process of reduplication, specifically the repetition of the single character 呵, which phonetically imitates a soft, breathy sound of laughter or exhalation. This doubling serves not to change the core meaning but to extend, soften, and emotionalize the sound, creating a distinct vocal texture that conveys a nuanced, often ambiguous, affective state, like light laughter, mild amusement, or non-committal acknowledgment, that a single instance of the sound could not achieve on its own.