Sound Quality and Clarity
Acoustics is the study of sound. In this section we're going to explore how sound waves travel from the vibrating vocal folds, through the vocal tract (throat), and out into the air. Sound is produced when air molecules get moved, and the movement continues in a wave, and thus when the sound is continuous (like the human voice) a continuous wave occurs.
Sound quality is separated into multiple factors, mainly being the frequency (a.k.a the Pitch of the voice) at which the voice is being produced (Hz) and the words per minute at which the voice is speaking at. Bellow are some examples of how a voice is changed as the frequency and pitch in Hz changes.
Demonstration #1 (Phrase: Gad, your letter came just in time)
When raising the frequency/pitch a softer and lighter voice will be produced.
Contralto, mean pitch (174 Hz)
Mezzo-soprano, mean pitch (246 Hz)
Soprano, mean pitch (348Hz)
By further raising the pitch by 6 halftones, a child voice is created:
Child, mean pitch (492 Hz)
On the other hand, by lowering the pitch , deep male voices can be created:
Baritone, mean pitch (87 Hz)
Bass, mean pitch (61 Hz)
Contra-bass, mean pitch (43 Hz)
By further lowering the pitch, the voice of a giant (extremely deep) is created.
Giant, mean pitch (31 Hz)
As you can tell, the higher the frequency, the higher pitch the voice is, and the lower the frequency, the lower the pitch of the voice is.But going too high or too low with the frequency will indeed affect the quality of voice. The "Giants" voice above you can begin to notice the decreased clarity in the voice, and it is harder to make out the words than lets say the child's voice.
Demonstration #2(Phrase: Gad, your letter came just in time)
To continue, changing the words per minute spoken, will also change the quality and clarity of the voice. Here are several examples of the same voice but at different speeds. *Number represents the words per minute*
speed_100_wpm
speed_200_wpm
speed_300_wpm
speed_400_wpm
speed_500_wpm
speed_600_wpm
speed_700_wpm
speed_800_wpm
speed_900_wpm
speed_1000_wpm
As you can probably hear, around the 500 - 600 wpm mark, understanding each word separately is much more of a struggle, rather than listening to it at under 600 wpm.
There are various other factors that play towards the clarity in speech such as punctuation, and various break ups and pauses between words.
Sound quality is separated into multiple factors, mainly being the frequency (a.k.a the Pitch of the voice) at which the voice is being produced (Hz) and the words per minute at which the voice is speaking at. Bellow are some examples of how a voice is changed as the frequency and pitch in Hz changes.
Demonstration #1 (Phrase: Gad, your letter came just in time)
When raising the frequency/pitch a softer and lighter voice will be produced.
Contralto, mean pitch (174 Hz)
Mezzo-soprano, mean pitch (246 Hz)
Soprano, mean pitch (348Hz)
By further raising the pitch by 6 halftones, a child voice is created:
Child, mean pitch (492 Hz)
On the other hand, by lowering the pitch , deep male voices can be created:
Baritone, mean pitch (87 Hz)
Bass, mean pitch (61 Hz)
Contra-bass, mean pitch (43 Hz)
By further lowering the pitch, the voice of a giant (extremely deep) is created.
Giant, mean pitch (31 Hz)
As you can tell, the higher the frequency, the higher pitch the voice is, and the lower the frequency, the lower the pitch of the voice is.But going too high or too low with the frequency will indeed affect the quality of voice. The "Giants" voice above you can begin to notice the decreased clarity in the voice, and it is harder to make out the words than lets say the child's voice.
Demonstration #2(Phrase: Gad, your letter came just in time)
To continue, changing the words per minute spoken, will also change the quality and clarity of the voice. Here are several examples of the same voice but at different speeds. *Number represents the words per minute*
speed_100_wpm
speed_200_wpm
speed_300_wpm
speed_400_wpm
speed_500_wpm
speed_600_wpm
speed_700_wpm
speed_800_wpm
speed_900_wpm
speed_1000_wpm
As you can probably hear, around the 500 - 600 wpm mark, understanding each word separately is much more of a struggle, rather than listening to it at under 600 wpm.
There are various other factors that play towards the clarity in speech such as punctuation, and various break ups and pauses between words.
Open And Closed Air Columns vs The Human Voice
The human voice works upon a long open end air column.
The open air column consists and is the length from the mouth all the way to the lungs. It is all one long tubular system that consists of multiple curves as well. It can be displayed from the picture on the side of this paragraph. It starts at the lung in which the voice starts. A rush of air comes up from the lungs at which is passes through the wind pipe (trachea), and the most important part is that it passes through the Vocal Chords. This is where the magic of physics occurs! The vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally, from back to front, across the larynx. They vibrate, modulating the flow of air being expelled from the lungs during phonation. The vocal fold vibratory cycle has phases that include an orderly sequence of opening and closing the top and bottom of the vocal folds, letting short puffs of air through at high speed. Air pressure is converted into sound waves.
Vocal fold vibration – sequence of vibratory cycles:
The open air column consists and is the length from the mouth all the way to the lungs. It is all one long tubular system that consists of multiple curves as well. It can be displayed from the picture on the side of this paragraph. It starts at the lung in which the voice starts. A rush of air comes up from the lungs at which is passes through the wind pipe (trachea), and the most important part is that it passes through the Vocal Chords. This is where the magic of physics occurs! The vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally, from back to front, across the larynx. They vibrate, modulating the flow of air being expelled from the lungs during phonation. The vocal fold vibratory cycle has phases that include an orderly sequence of opening and closing the top and bottom of the vocal folds, letting short puffs of air through at high speed. Air pressure is converted into sound waves.
Vocal fold vibration – sequence of vibratory cycles:
- Vocal folds are moved to midline by voice box muscles, nerves, and cartilages
- The vibratory cycle occurs repeatedly; one vibratory cycle is as follows:
- Column of air pressure opens bottom of vocal folds
- Column of air continues to move upwards, now towards the top of vocal folds, and opens the top
- The low pressure created behind the fast-moving air column produces a “Bernoulli effect” which causes the bottom to close, followed by the top
- Closure of the vocal folds cuts off the air column and releases a pulse of air
- New cycle repeats
- The rapid pulses of air created by repeat vibratory cycles produce “voiced sound” which is really just a buzzy sound, which is then amplified and modified by the vocal tract resonators, producing voice “as we know it.”