Is it good to say “um”?

Disfluencies such as pauses, “um”s, and “uh”s are common interruptions in the speech stream. Previous work probing memory for disfluent speech shows memory benefits for disfluent compared to fluent materials. Complementary evidence from studies of language production and comprehension have been argued to show that different disfluency types appear in distinct contexts and, as a result, serve as a meaningful cue. If the disfluency-memory boost is a result of sensitivity to these form-meaning mappings, forms of disfluency that cue new upcoming information (fillers and pauses) may produce a stronger memory boost compared to forms that reflect speaker difficulty (repetitions). If the disfluency-memory boost is simply due to the attentional-orienting properties of a disruption to fluent speech, different disfluency forms may produce similar memory benefit. Experiments 1 and 2 compared the relative mnemonic benefit of three types of disfluent interruptions. Experiments 3 and 4 examined the scope of the disfluency-memory boost to probe its cognitive underpinnings. Across the four experiments, we observed a disfluency-memory boost for three types of disfluency that were tested. This boost was local and position dependent, only manifesting when the disfluency immediately preceded a critical memory probe word at the end of the sentence. Our findings reveal a short-lived disfluency-memory boost that manifests at the end of the sentence but is evoked by multiple types of disfluent forms, consistent with the idea that disfluencies bring attentional focus to immediately upcoming material. The downstream consequence of this localized memory benefit is better understanding and encoding of the speaker’s message.

That is from a recent paper by Diachek, E., & Brown-Schmidt, S., via Ethan Mollick.