相槌 (back-channeling)

The Japanese conversational practice of giving frequent verbal and nonverbal acknowledgments — はい, ええ, うん, なるほど, nodding — during another person's speech to signal active listening. Far more frequent and expected than English 'mm-hmm' or 'yeah'; silence during a long stretch of someone else's speech can feel rude or disengaged. A core feature of Japanese conversational culture, named with either the kanji 相槌 (あいづち) or the kana あいづち.