Riiak khao translates from Thai as 'incoming call' or 'call coming in,' and clips like this circulate as novelty ringtones on soundboards where users upload literal voice announcements instead of musical tones. With no documented artist, show or movie source, the sound spread purely as a user-shared utility clip, valued for its clarity and the joke of hearing the function spoken aloud. It remains popular among Thai speakers and learners who want a distinctive, language-specific alert that stands out from default phone tones.