Why Is Background Conversation Harder to Ignore Than a Steady Hum?

When you are trying to remember a short number in an office, nearby conversation is often more disruptive than the steady hum of air conditioning. This is not only because speech is ‘interesting’. Experiments on the irrelevant sound effect find that changing speech or tones can impair the ordered recall of items that people have just seen, even when they are told to ignore the sound. A steady, repetitive sound contains less change and is less likely to compete with the order being maintained.

Intelligible conversation can add another kind of interference. Reading and writing already require the processing of meaning, so clearly understood sentences nearby can automatically compete for similar processing. An occasional personally relevant word may also capture attention directly. Reducing the intelligibility of speech can therefore matter more than lowering it by a few decibels.

The finding should not be expanded into ‘all speech is worse than all noise’. The task matters: remembering an ordered number, proofreading prose and making a spatial judgement do not have identical vulnerabilities. Acoustic variation, intelligibility and individual differences also change the result. A meta-analysis of auditory distraction during reading found uncertainty about effect sizes and their real-world significance, so a laboratory average cannot predict every person's work on a particular occasion.

My view is that distraction is not simply evidence of weak will; it reflects competition between a task and its sound environment. When exact wording or order must be retained, making conversation less intelligible or moving somewhere quieter is usually more reliable than commanding yourself not to listen. A steady sound is not a treatment; in this comparison, it merely introduces less change and meaning.

https://pmc.ncbi.nlm.nih.gov/articles/PMC9950248/
https://doi.org/10.1177/1745691617747398