art
Sine Wave A 440 Hz Concert Pitch for Ten Hours
Stop your brain from overthinking. You don't need an app. Ten hour Sine wave with no overtones which is called pure as it is only the fundamental frequency.
Youtube
Born prematurely at just 25 weeks, Derek Paravicini has suffered from blindess, learning impairment and severe autism for his entire life. Despite his impairment, Derek has the unique gift of perfect pitch, and is able to play any piece of music after hearing it only once.