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