The evidence library
Infant sleep research, explained
Older studies still shape the advice parents hear. We explain the question each study asked, what it found, and where its answers stop.
By the Lullasure editorial team. Source checked, not independently clinically reviewed. Read our editorial policy.
What did the 1990 white noise study actually show?
What Spencer’s small newborn trial found about falling asleep, why it cannot answer all-night safety questions, and how to read the result today.
Read the explainer A study in plain languageDid the 2014 study show that sound machines cause hearing loss?
Hugh’s study measured maximum machine output. Understand its distances, the 50 and 85 dBA comparisons, and why it did not measure hearing loss in babies.
Read the explainer A study in plain languageWhat did the 2021 white noise devices study find?
What Hong and colleagues found when testing eight machines and six iPhone apps—and why a distance comparison does not establish infant safety.
Read the explainer A study in plain languageWhy does the 1979 infant night-waking study still matter?
How early home video research changed the question of sleeping through the night, what the original abstract reports, and what parents should not infer.
Read the explainer A study in plain languageWhat does the 2024 white noise review tell parents?
Read the 2024 review through its search cutoff, mixed populations, and evidence limits.
Read the explainerKeep the key numbers in context: download our source map, study card, and nursery measurement checklist.
Read the white-noise volume guide. Every explainer distinguishes the study result from our interpretation.
Download the evidence index (JSON) · Follow new articles by RSS. The index contains our article summaries and source references, not original laboratory measurements.