Sound

Sound, short for sounding, is a BDSM and medical-play act tag describing the insertion of a smooth, slender rod or instrument into the urethra for stimulation. In fiction it's typically framed as an extreme or clinical-feeling act tied to medical-fetish or hardcore BDSM settings, and it's tagged specifically rather than folded into general bondage content. It's a niche but recurring category within kink-focused doujinshi. Readers looking for sound hentai comics can find a dedicated, if smaller, selection in Top Hentai's catalog.