Is bass important in audio? Part 2
The voices and sounds of the musical instruments that we make are not a single sound, but a combination of multiple pure tones.
Everyday sounds heard by superimposing pure tones are called “compound sounds.”
The decomposition of a complex sound with a complex waveform produces a pure tone.
On the other hand, “noise”, which is avoided even in audio, is one of the types of sound.
The noise waveform is a completely random and chaotic waveform.
When buying new audio, some people may adjust it to white noise or pink noise when you keep the sound flowing for a long time as you age to get used to the high and low frequencies.
White noise is noise with the same energy in all frequency bands.
Pink noise is white noise that passes through a -3dB / oct LPF and is inversely proportional to the pitch (frequency) of the sound.
It is often used to measure sound because the sound gets smaller as the sound gets louder.
However, this noise is also an element that enriches the music.
The GAIN (distortion) of a band’s music is easy to imagine, but in the 20th century, composers actively adopted noise as a material for music.
Many musical instruments also contain a small amount of noise. Without this slight noise, the unique flavor of the instrument will be affected.
Treble and bass characteristics
Wave propagation
The treble has the property of going in a straight line.
On the other hand, the bass has the property of spreading 360 degrees like waves on the surface of the water.
For example, sirens such as ambulances with relatively high-pitched sounds have different tones depending on the direction.
This type of range influences the phenomenon that when you approach the clubhouse, you feel like only the bass is playing.
And the speed at which sound is transmitted changes depending on the range.
The speed of sound increases with high frequencies and slows down with low frequencies.
It is easy to understand if you imagine fireworks.
You can hear the explosion sound (bass) with a long delay to the sound of fireworks going up.
How humans recognize sound
Illustrated illustration of ears
So what is the mechanism by which humans perceive these sounds?
If you follow the mechanism of the ear, the vibration of the air is first picked up by the earlobe.
Then the vibration reaches the eardrum through the ear canal (auditory canal), and the vibration is transmitted from the spiral organ (cochlea) to the auditory nerve → brain through the ear bone called the ossicle.
It’s a simple explanation, but our ears can finally recognize sound in the brain through that process.
As for the audio, it can be seen that the ears that handle the sound are a very delicate sensory windpipe.
How you listen to it depends on the frequency! Equal volume curve
And since the human ear has a filter function that passes only specific frequencies, it is possible to distinguish between high and low sounds and even chords.
In fact, the human ear has the superiority of sounds that can be heard well and sounds that are difficult to hear, and the way they are heard changes depending on the nature of the sound.
The frequency that humans can hear is said to be 20 Hz to 20,000 Hz, but it also depends on the volume of the sound.
As you can feel, high pitched sounds are easy to hear even with low pitched sounds, but there are some frequency bands that are difficult to hear unless the sound is loud.
