Matt returns today to explain why humans didn't evolve for silent sleep. Citing the Hadza and the brain's "open microphone," he explains how we process sound for safety even while resting. He details the "first-night effect," where half the brain stays alert in new environments, demonstrating that our ears never truly switch off.

Our host weighs the benefits of noise machines for memory against the risks of dream sleep suppression. He offers evidence-based tips for parents and travelers on using sound effectively, suggesting that earplugs may be better for loud, intermittent noise. He concludes that we should seek "acoustic companionship" rather than total silence to align with our evolutionary design.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

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As always, if you have thoughts or feedback you’d like to share, please reach out to Matt:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube: https://www.youtube.com/channel/UCA3FB1fOtY4Vd8yqLaUvolg