Is it suitable for a singer with a loud voice? What is the physical principle of loud sound?

A loud voice is not necessarily suitable for being a singer. There is no absolute relationship between the two.

John Smith, a biophysicist and acoustics expert at the University of New South Wales, explained: "This kind of sound that can travel far away carries a tone, which will strongly resonate with people's vocal tract and ears. Its penetrating power is very strong, and its frequency is about 3000 Hz, or 3000 times per second: it is similar to the frequency of scraping the blackboard with nails. "

In contrast, most people's voice frequency is in the mild range of 80 Hz to 250 Hz.

So, how do people who speak loudly produce deafening high-frequency sounds? To understand this matter, we must first understand the principle of pronunciation.

We produce sound by rapidly vibrating two thin mucous membranes in the throat (called vocal cords). The reciprocating motion of these vocal cords interrupts the airflow from the lungs, leading to the "inhalation" of sound. If the vocal cord swings back and forth 100 times per second, it will produce a frequency of 100 Hz per second. The extra movement of vocal cords (such as collision) will produce additional frequencies several times the fundamental frequency: 200 Hz, 300Hz, 400Hz and so on.

All these frequencies pass through the channel together, and according to its shape, the channel resonates at these specific frequencies. Just as an organ increases the amplitude of sound waves passing through it, the resonance of a channel will amplify those resonance frequencies and make the sound louder.

This is the trick: whether subconsciously or intentionally, loud speakers have learned to use the natural resonance of their vocal cords to increase their volume. First, they control the vocal cords to generate harmonic frequencies of about 3000 Hz. This involves using stronger airflow from the lungs and controlling the vocal cords, and then generating a large number of high-frequency harmonics, while most people mainly generate low-frequency harmonics.

Second, change the shape of the sound channel. By narrowing or limiting the channel directly above the vocal cord, it will resonate at this high frequency, making the high-frequency sound louder. The improvement of this sound appears in the frequency range where the human ear is sensitive and the background noise is small.

Recent research by Smith and his colleagues shows that singers make similar adjustments to their vocal tract to make their voices better. Scientists have successfully described how to do this at different pitches. A research report published in the Journal of the American Acoustical Society shows that even trumpeters are controlling their sound resonance to play very high notes.