Associations Between Sound Levels and Sleep Architecture: Implications for Sleep Disparities.

Poor sleep is more common among some social groups (e.g., minoritized race or lower socioeconomic status). One potential source of sleep disruption is noise. Our goal was to examine whether sound levels varied between two racial groups and education level and whether sound levels were associated with sleep architecture in a real-world setting. Sound was measured using a sound meter while simultaneously recording polysomnography for one night in participants' bedrooms to quantify sleep stages, non-rapid-eye movement (NREM), and REM sleep. Our sample included 26 Black and 28 White adults aged 21-50 years; 22 (41%) had > college degree. On average, sound levels were higher in the bedrooms of Black participants compared to White participants. Black participants also had significantly less total sleep time, N3, REM, REM%, and higher N2%. Those with college degree or less had lower N3%. Higher average sound levels during the entire sleep period were significantly associated with fewer minutes of REM (β = -1.50, p = 0.008), lower REM% (β = -0.32, p = 0.002), and higher N2% (β = 0.43, p = 0.007) but was not associated with other polysomnography measures. Sound levels were estimated to explain 14.5% of the difference in REM minutes and 21.1% of the difference in REM percentage between races and 6% of the difference in N3% between education groups. In summary, greater sound levels were associated with less REM sleep and greater N2%, and average sound levels were higher in the homes of Black participants. Environmental noise may be one factor associated with sleep disparities.