People hum for several reasons, such as to calm nerves, feel happier and reduce stress. People hum unconsciously and consciously. Many use humming as a simple and effective way to ease tension and reduce stress and often derive health benefits in the form of improved sinus health in the process.
The idiom may call laughter the best medicine, but humming is not far behind. Simply humming a song for less than 30 seconds is enough time to make people feel less anxious and is sufficient for improving sinus health too. Humming creates vibration in the sinus cavity, which helps to eliminate congestion.