Why Do Men Have a Lower Fundamental Frequency Than Women?

A fundamental frequency is the lowest frequency at which any object vibrates. Frequency is measured in Hertz, or Hz, and the pitch of a person's voice is determined by the fundamental frequency of their vocal chords. There are several physiological reasons why men have a lower fundamental frequency than women.

Body Size

• According to the National Center for Voice and Speech in Iowa, a bigger instrument has a lower fundamental frequency than a smaller one. A double bass, for example, is the same shape and design as a violin, but being larger, it produces a lower sound. In people, the same rule applies. A baby's fundamental frequency is roughly 500 Hz, which is much higher than a grown woman, whose fundamental frequency is 200 Hz. A man's fundamental frequency is usually around 125 Hz.

Laryngeal Size

• The Larynx is a 2-inch long, tube-shaped organ in the respiratory tract that contains the vocal chords that produce vocal sounds. Its size affects fundamental frequency. Measured along the length of the vocal folds, a man's larynx is on average about 40 percent longer that of a woman. This extra length means that it produces a lower sound.

Vocal Tract

• The vocal tract is the length, or tract, the voice travels before developing into a sound. Vocal tract length, or neck length, is hereditary. The National Voice Center in Iowa has found that people with long necks have a lower fundamental frequency than people with short necks. However, trained singers and speakers learn techniques to control the length of the vocal tract by raising or lowering the larynx, and can therefore alter the pitch or fundamental frequency of their voices.

Vocal fold

• Another measurement that can explain why a man has a lower fundamental frequency than a woman is the length of the vocal fold that is used to create a sound. This is called"'effective vocal fold." Men have extra space in their necks for the Adam's Apple, and that means they have a longer effective vocal fold length. The amount of vocal fold vibrating in a man's throat is about 60 percent more than in a woman's, and makes a significant difference in the fundamental frequencies of men and women.