Pitch vs. Frequency: Key Differences Explained

This article explains the difference between pitch and frequency, two terms commonly associated with audio signals.

Microphones and speakers are crucial audio frequency devices that convert acoustic energy into electrical energy and vice versa. These devices play a vital role in how we interact with sound.

Pitch

• Pitch is a subjective quality, similar to loudness.
• It’s important to understand that pitch depends on the intensity of the audio signal, not just the frequency. This means you can change the perceived pitch by altering the intensity, even if the frequency remains constant.
• The unit of pitch is the “mel.”
• Definition: A pure tone with a frequency of 1000 Hz and a loudness of 1 sone produces a pitch of 1000 mels.

Frequency

• As defined in Wikipedia, frequency is “the number of occurrences of a repeating event per unit of time.”
• In simpler terms, it’s the number of cycles per second.
• The SI unit of audio frequency is Hertz (Hz).
• Example: If there are 100 cycles per second, the frequency is 100 Hz.
• Humans can typically hear frequencies ranging from 20 to 20,000 Hz.
• The audible frequency range can be affected by environmental factors.
• The ear is better at judging frequency ratios than absolute frequency differences.

Key Differences Between Pitch and Frequency

• The relationship between pitch and frequency is nonlinear. For instance, while 1000 Hz corresponds to 1000 mels, a frequency of 2000 Hz maps to a pitch of only 1500 mels.

• Vocal Fold Length: Male vocal folds are typically 17 mm to 25 mm long, while female vocal folds are 12.5 mm to 17.5 mm long. This difference in length contributes to the different pitch ranges in men’s and women’s voices. Men often speak at frequencies between 65 and 260 Hz, while women typically speak in the range of 100 to 525 Hz.

• A healthy young person can usually hear frequencies from 20 Hz to 20 kHz.