Sounds Perceptible by the Human Ear and the Decibel Scale
The human ear is capable of perceiving a wide range of sounds, from the faintest whispers to extremely loud noises. To measure and describe these sounds, a logarithmic scale called the decibel scale (dB) is used. This scale reflects the non-linear way in which the human ear perceives the intensity of sound waves.
The sounds detected by the human ear range from the threshold of hearing, which is the faintest detectable sound (approximately 0 dB, equivalent to 10^-12 watts/m²), to the threshold of pain (approximately 120-130 dB), representing very high sound intensities.
Like the Richter scale for measuring earthquakes, the decibel scale is logarithmic. This means that volume is not directly proportional to the intensity of sound. Instead, the intensity of a sound increases very quickly. A sound at 20 dB is 10 times more intense than a sound at 10 dB and would be perceived as twice as loud.
The decibel scale is essential for understanding and effectively communicating about noise levels, whether assessing risks to hearing health or optimizing acoustics in a specific environment.
Headphones and earbuds can reach sound levels of 100 dB or more, so a safe listening level is between 50% and 60% of the maximum volume. This helps protect our hearing and allows us to enjoy our favorite music for longer.
Sound levels for nonlinear (decibels) and linear (intensity) scales:
Decibels Intensity (in watts per square meter) Type of Sound
130 10 Nearby artillery fire (threshold of pain)
120 1 Amplified rock music; near a jet engine
110 10⁻¹ Loud orchestral music, in the audience
100 10⁻² Electric saw
90 10⁻³ Inside a bus or truck
80 10⁻⁴ Inside a car
70 10⁻⁵ Average street noise; loud telephone bell
60 10⁻⁶ Normal conversation; business office
50 10⁻⁷ Restaurant, private office
40 10⁻⁸ Quiet room at home
30 10⁻⁹ Quiet classroom; bedroom
20 10⁻¹⁰ Radio, television, or recording studio
10 10⁻¹¹ Soundproof room
0 10⁻¹² Absolute silence (lower threshold of hearing)
The Brain as a Dynamic Equalizer
The human brain is remarkable, capable of adapting to various environments. One fascinating aspect of this adaptability is its ability to adjust audio perception based on the surrounding space. In essence, the brain functions as a dynamic equalizer, fine-tuning sound according to the perceived environment.
Factors like the size, shape, and materials of a space play significant roles in how the brain interprets sound. A small, enclosed space with hard surfaces, such as a bathroom, may create a sharp sound, while a large, open area with soft furnishings, like a concert hall, produces warmer, fuller acoustics.
The brain’s ability to adjust audio perception is essential. By combining visual and auditory cues, the brain can modify the perceived sound, helping us interpret and adapt to our surroundings.
Visual Voice
Interactive project with sound and visual elements
Cristina Pop-Tiron | Fetelors Studio
The voice creates invisible waves that surround us, conveying emotions and thoughts.
But what do these waves look like? How can we see the sounds we produce?
“Visual Voice” is a journey where the invisible becomes visible. Every word, whisper, or melody generates vibrations that are transformed here into a visual experience. This bridge between sound and image allows us to see our voice and explore a new dimension of sound. Speak, sing, or whisper into the microphone and watch your voice come to life.