Sound Components (Buzzer)What is sound component?

Basic knowledge of Piezoelectric Sound Components

What is buzzer?

Buzzer is a component producing sound of alarm and electronic sound.
Ex) Security buzzer, fire-alarm device and alarm clock etc.

Buzzer plays an important part as a man-machine interface.

The buzzers which apply piezoelectric ceramics are "Piezoelectric Buzzers".
We generally call “buzzer”, however, a formal name is “piezoelectric sound component”.

What is sound?

Sound is a vibration of air.

What is sound
  1. Sound source
    pushes air
  2. Atmospheric pressure changes.
    (sound waves)
  3. Vibration of the
    eardrum
  4. The vibration is perceived
    as sound.

Air pressure is called Sound Pressure when a sound is propagated through the air.
The number of times of the dilatational wave of air per a second is frequency.

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Sound Pressure Level loudness of sound [dB] Higher sound pressure level = Louder sound
Frequency pitch of a sound [Hz] Higher frequency = Higher-pitched sound

A sound component produces a sound like this.

Loudness and pitch of sound

Sound Pressure Level (loudness of sound)

Minimal loudness of sound perceived by human is defined as 0dB (20μPa). Sound pressure that Murata’s sound component produces is approximately 70 to 90dB (measured in 10cm distance).

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whispering voice approx. 20dB
usual conversation approx. 60dB
sound of train underpass approx. 100dB

The more distant the receiver is from sound source, the lower sound gets.

"Specification of Sound Pressure Level "→ The necessary information are the distance from the sound source and how loud the sound should be there.

Specification of Sound Pressure Level
Frequency(Pitch of a sound)

In general, man’s audible frequency range is about 20 Hz to 20 kHz.
Especially, the frequency range of 2 kHz to 4 kHz is the most audible.
For this reason, the most of piezoelectric sound components are used in this frequency range.

  • *It is slightly hard for older persons to hear the frequency range of over 3 kHz.
Frequency(Pitch of a sound)

Murata's Sound Components(Buzzer)