In the study of acoustic phenomena, students often fall into some common misunderstandings, resulting in inaccurate understanding or improper application of concepts. This article will analyze these common pitfalls to help students better grasp the relevant knowledge of acoustic phenomena.
Pitfall 1: The vibration of the sound source stops, and the sound disappears with it?
"Sound stop" means that the sound source no longer vibrates and stops propagating outwards, but the originally transmitted sound waves still continue to propagate. Without considering the loss of sound, after the sound source stops vibrating, people who are different from the sound source can still hear the original sound one after another, and the sound does not disappear when the vibration of the sound source stops.
Pitfall 2: As long as there is vibration, you must be able to hear the sound?
Sound is produced by the vibration of an object, but not all of the sound produced by vibration is audible to us. There are four main reasons:
1.The propagation of sound requires a medium, and it cannot propagate in a vacuum.
2.Limitations of the human ear and auditory system.
3.The loudness of the sound must be loud enough to cause the eardrum in the human ear to vibrate for the person to hear.
4.The person's sense of hearing must be normal.
Pitfall 3: Tone, loudness and timbre are indistinguishable.
Pitch generally refers to the height of the sound, which is related to the frequency, and is also related to the length, thickness and tightness of the vocal body; Loudness generally refers to the magnitude of the sound, which is related to the amplitude, and also related to the concentration of the sound and the distance from the emitter. Timbre can distinguish between different vocal bodies, and is related to the material and structure of the vocal bodies.
Pitfall 4: The application of echolocation is error-prone.
Echo is the sound that comes from the sound source, is reflected back when encountering obstacles such as cliffs and walls, and then enters the human ear. Can you measure distance with echoes? For example, to measure the distance between the emitter and the obstacle, the emitter emits a specific sound, receives the echo signal, records the time interval t between the echo and the original sound, and finds the distance under the condition of detecting the sound propagation speed.
Pitfall 5: The concept of noise is prone to error.
There are two ways to define noise: one is from a physical point of view, and the other is from an environmental point of view. It should be said that a sound that fits one of them is noise, so a musical sound can become noise in different environments.
Through the above analysis, we can see that students need to pay attention to some common pitfalls when learning about acoustic phenomena. Only by accurately understanding the concepts and mastering the relevant knowledge points can we avoid making mistakes in these pitfalls. At the same time, doing more practice problems is also an effective way to improve your problem-solving ability.