Sound Produced by Humans

Question 1 What is the length of vocal cords in a man?

Question 2 Out of a man and a woman who has shorter vocal cords?

Question 3 Out of a man and a woman who produces sound of higher pitch?

Question 4 Name the sound producing organs in humans?

Question 5 Which part of the body vibrates when we speak?

Question 6 What is the name of the strings in human voice box which vibrate to produce sound?

Question 7 Describe how sound is produced by the human voice box?

Question 8 What is the frequency of the sound produced when the vocal cords are tight and thin?

Question 9 What is the frequency of the sound produced when the vocal cords are loose and thick?

Question 10 Why are the voices of men, women and children different?

Larynx

The human beings produce sound by using the voice box which is called larynx.

The voice box is situated in our throat at the top of the windpipe.

Vocal Cords

The human voice box contains two ligaments known as vocal cords .

Sound is  produced by the vibrations of vocal cords. The vocal cords are attached to muscles which change the tension or stretching in the cords and the distance between the cords.

(1) The muscle of vocal cords are completely relaxed due to which the vocal cords are separated and loose so that air from the lungs passes through them without producing any sound. When we are not talking or singing, the two vocal cords are far apart with a lot of gap between them.

 

(2) When we want to speak, the muscles of vocal cords contract due to which the two vocal cords become stretched and close together leaving only a narrow slit between them. The lungs pass a current of air between the two vocal cords. This air makes the vocal cords vibrate. And the vibrating vocal cords produce sound. When we talk or sing we actually make our vocal cords vibrate. And vibration of vocal cords by expelled air produce vocal sounds.

Activity

Take two rubber strips of same size. Place these two rubber strips one over the other. Hold the two ends of the rubber strips in your hands and stretch them tightly. Keep the stretched rubber strip in front of your mouth and blow air through the thin gap between them. As the air blows through the stretched rubber strips, a sound is produced. This sound is produced by the vibration of stretched rubber strips when air rushes through the thin gap between them.

When the muscles attached to vocal cords contract and stretch, the vocal cords become become tight and thin and a sound of high frequency is produced. when the muscles relax, the vocal cords become loose and thick, and a sound of low frequency is produced.

The vocal cords of a man are 20 mm long. The vocal chords of a woman are 5 mm shorter than man. Due to the shorter vocal cords, the frequency of a woman’s voice is higher than that of a man. Small children have very short vocal cords due to which the frequency of their voice is very high. This is why their voice is shrill. It is due to the different frequencies caused by the different length of their vocal cords that the voice of men, women and children are different.