1.只要有振动,就一定有声音.这种说法正确吗?应怎样理解? 答:这种说法不正确.从声音的产生和传播来看,正常人听到声音必须同时具备两个条件.一是发声体振动,发出人耳可以听到的声音.有无声音是由人的听觉决定的,正常人只能听到20-20000 Hz范围内的声音,听不到低于20 Hz的次声和高于20000 Hz的超声.例 1. As long as there is vibration, there must be a voice. Is this correct? How should it be understood? Answer: This is incorrect. From the point of view of sound production and dissemination, normal people must have two conditions to hear the sound. The first is that the sounding body vibrates and sounds that can be heard by the human ear. The presence or absence of sound is determined by human hearing. Normal people can only hear sounds in the range of 20-20000 Hz, and can hear no sounds below 20 Hz. Acoustic and ultrasound above 20000 Hz.