AM radio can be sent over larger distances, but the quality of the sound is not as good as a later kind of radio signal processing, called frequency modulation.

调幅广播可以发送更远的距离，但它的声音质量却不及后来一种被称为频率调制的无线电信号处理方式优越。

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The system can issue a pure tone, tone twitter, narrowband noise and natural sound of the voice signal, and can adjust the loudness and frequency of the signals with some accuracy.

该系统能发出纯音、啭音、窄带噪声和自然声等声音信号，并可对信号进行一定精度的响度和频率调节。

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The frequency of the sound wave is controlled by the feedback signal of the system.

声光晶体由行波场驱动，声场频率则由系统的反馈讯号控制。

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AM radio can be sent over larger distances, but the quality of the sound is not as good as a later kind of radio signal processing, called frequency modulation.

VOA: special.2010.12.08

Furthermore, the LightSpeaker's 2.5-inch wide dispersion driver uses digital signal processing to optimize high- and low-frequency output for a full spectrum of sound.

ENGADGET: Klipsch LightSpeaker makes whole home audio as simple as screwing in a light bulb (hands-on)