Why does helium change people's voice?

Because helium travels almost three times as fast as air, people who inhale helium will speak more frequently. This interesting phenomenon makes people who inhale helium speak in a shrill voice, and men suddenly become sissy, just like anime characters in the old days.

Helium is a colorless and odorless gas at room temperature and atmospheric pressure. Its volume content in dry air is 5.24× 10-6. It is the substance with the lowest critical temperature found by human beings. Dark yellow when discharged at low voltage.

The vibration of vocal cords itself is not very strong, which requires the vibration of the surrounding tracheal cavity. * * The intensity of vibration is determined by the wavelength, and waves with an integer multiple of the wavelength are easy to vibrate. Now the gas in the trachea has changed, and the speed of sound waves has also changed. In order to keep the wavelength constant, the frequency must be changed accordingly.

Extended data:

The speed of sound of helium is nearly three times that of air, so the vibration frequency of helium is also three times. So the original pitch * * * vibrates and amplifies well, and now the overtone * * * with higher frequency vibrates well, and the overall timbre gives people the feeling of "high frequency". But if you want to say "tone", it hasn't changed.

Because of the low temperature of liquid helium, the resistance of some metals or metal compounds will disappear completely when cooled with liquid helium. This phenomenon is called superconductivity and this temperature is called critical temperature.

Because helium travels almost three times as fast as air, people who inhale helium will speak more frequently. This interesting phenomenon makes people who inhale helium speak in a shrill voice, just like cartoon characters in the old days.

Baidu encyclopedia-helium