Effect on humans – 2026 placebo-controlled study highlights
ORIGINAL RESEARCH article
Front. Behav. Neurosci., 26 April 2026
Sec. Individual and Social Behaviors
Volume 20 - 2026 | https://doi.org/10.3389/fnbeh.2026.1729876
36 people (university students) were exposed to inaudible low frequency sound or no low frequency sound overlaid over both soothing and unsettling music in controlled lab
Infrasound was applied at 75-78 dB
Regardless of type of music – subjects were unable to determine when infrasound (low frequency below 20 Hz)
When infrasound was overlaid on music – within 1 hour session
Salivary cortisol (stress hormone) was statistically Increased
Agitation score was statistically higher
During control – soothing or unsettling music without infrasound
No cortisol increase was measured
Cortisol peaks in the morning and decreases through the day reaching minimum around bedtime – even small increases at night cause sleep disturbance
Agitation score was not elevated