♦What is a vibration speaker?
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The vibration speaker is a newly developed speaker components capable of generating both vibration and sound. |
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Different types of input signals are used to generate vibration and sound. |
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As a result... |
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The vibration speaker is ideal for space-limited applications such as mobile terminals. The compact design helps to reduce the overall size and weight of the terminal. |
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Complex vibrations can be produced by modifying the input signal. For instance, bass notes can be converted into vibration.
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The design of the vibration speaker is based on an ordinary dynamic speaker, consisting of a diaphragm, magnetic circuit, springs, coil and housing. |
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Sound is air vibration. Sound is perceived when air vibration reaches the ears and causes the eardrums to vibrate.
♦What is air vibration?
Objects make sounds when they are hit. This is due to vibration caused by the shock transmitted to the air. Beating a drum, for instance, causes the top of the drum to oscillate, which in turn vibrates the surrounding air. |
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The air is alternately pushed and pulled by the vibrating drum skin as shown above. The ongoing repetition of pushing and pulling (i.e., oscillation) produces sound.
♦What is the difference between high-pitch and low-pitch sound?
Air vibration is perceived by our ears as sound. The speed of vibration, called the frequency and expressed in Hz, represents the number of oscillations per second. The higher the frequency (i.e. the greater the number of oscillations per second), the higher the pitch. Conversely, the lower the frequency, the lower the pitch.
♦Why does pitch vary?
Every object has a resonant frequency which is the frequency at which the object vibrates most readily. Small objects vibrate easily and therefore tend to produce high-pitched sounds, whereas large or soft objects do not vibrate as easily and tend to produce low-pitched sounds. On a xylophone, for instance, the length of the bars determines the resonant frequency and therefore the pitch.
♦What is the difference between loud and soft sound？
The sound level, expressed as decibel (dB), is the amount of variation in air pressure that produces sound. A large variation in air pressure (i.e. a large amount of air vibration) is perceived as loud soundly, while a small variation in air pressure is perceived as quiet sound. The human ear detects some frequencies better than others, so certain frequencies sound louder even at the same air pressure level. Our ears are highly attuned to frequencies around 4 kHz, the frequency produced by a baby crying or a woman screaming, but less receptive to very low and very high frequencies. The phon is commonly used as a measure of loudness based on the characteristics of the human ear. A sound pressure level of 40 dB at 1 kHz is defined as 40 phon. |
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