多选题
What topics do the speakers discuss?
Click on 2 answers.
Click on 2 answers.
【正确答案】
B、C
【答案解析】[听力原文]
W: Professor King?
M: Hello, Ashley. How are you?
W: I"m okay, but, to be honest, I"m totally confused about today"s lecture, especially the part about music and noise.
M: Oh. All right. Tell me what"s confusing.
W: I"m not sure I get what, what"s the difference between music and noise. You said, um, you said that noise is a random sound, and then you said the sounds of a cymbal and a drumbeat are examples of noise. But I think the sound of a cymbal or a drumbeat are examples of music because they"re made by musical instruments. What am I missing?
M: Oh, well, you said that noise is a random sound.
W: Uh-huh.
M: That"s correct. Noise is a random sound. It"s a random sound that has irregular sound waves.
W: But how"s a sound that"s noise different from a sound that"s music?
M: Well, think of it this way. If you could take a picture of a musical note, you"d see that it has regular waves that repeat themselves. That"s because music is a sound with a pattern we can hear or discern. Noise is different from music because it doesn"t have a pattern. A drumbeat is about as close as a musical instrument can get to making just noise. A single drumbeat is like a single word spoken out of context. A single word, all by itself, with no context, is like a random sound, just noise.
W: Hmm. I get it now. Even a musical instrument can make a random sound. Just noise.
M: Yes.
W: The other thing I don"t get is what you said about antinoise. I understand noise, but antinoise? I"m lost.
M: Think of antinoise as the opposite of noise.
W: I"m trying to, but it doesn"t make sense.
M: It"s like...uh...wait, let"s try this. Sound has waves, right?
W: Right.
M: Well, we can describe these waves as in phase or out of phase with each other. "Out of phase" means reversed.
W: Uh-huh.
M: If you add two out-of-phase waves together at the same frequency, the result is antinoise—otherwise known as silence.
W: Antinoise is silence.
M: Right! And there"s a program that proves this. A microphone picks up the sound and sends it back to the computer, and then the computer reads the waves and makes sort of a mirror image, or a reverse copy of the wave. Then you can play it back against the original sound, and when the two waves meet, they sort of overlap each other, exactly at the high and low peaks. This eliminates the sound and creates zero sound: antinoise. It"s all in your textbook. Did you read the chapter on noise and antinoise?
W: No, I didn"t have time. I guess I have some catching up to do.
M: Yes, you do. Go read the chapter. But, you know, it"s better to do the reading every week before the lecture. You"ll have a better idea of what we cover in class.
W: Yes, I know. You"re right. I guess I"d better go do that. Thanks, professor. I appreciate your help.
M: You"re welcome. See you later.
What topics do the speakers discuss?
The speakers discuss how music differs from noise: I"m not sure I get what, what"s the difference between music and noise; ...bow"s a sound that"s noise different from a sound that"s music; Noise is different from music because it doesn"t have a pattern. They also discuss the meaning of antinoise: The other thing I don"t get is what you said about antinoise; Think of antinoise as the opposite of noise; ...the result is antinoise—otherwise known as silence.
W: Professor King?
M: Hello, Ashley. How are you?
W: I"m okay, but, to be honest, I"m totally confused about today"s lecture, especially the part about music and noise.
M: Oh. All right. Tell me what"s confusing.
W: I"m not sure I get what, what"s the difference between music and noise. You said, um, you said that noise is a random sound, and then you said the sounds of a cymbal and a drumbeat are examples of noise. But I think the sound of a cymbal or a drumbeat are examples of music because they"re made by musical instruments. What am I missing?
M: Oh, well, you said that noise is a random sound.
W: Uh-huh.
M: That"s correct. Noise is a random sound. It"s a random sound that has irregular sound waves.
W: But how"s a sound that"s noise different from a sound that"s music?
M: Well, think of it this way. If you could take a picture of a musical note, you"d see that it has regular waves that repeat themselves. That"s because music is a sound with a pattern we can hear or discern. Noise is different from music because it doesn"t have a pattern. A drumbeat is about as close as a musical instrument can get to making just noise. A single drumbeat is like a single word spoken out of context. A single word, all by itself, with no context, is like a random sound, just noise.
W: Hmm. I get it now. Even a musical instrument can make a random sound. Just noise.
M: Yes.
W: The other thing I don"t get is what you said about antinoise. I understand noise, but antinoise? I"m lost.
M: Think of antinoise as the opposite of noise.
W: I"m trying to, but it doesn"t make sense.
M: It"s like...uh...wait, let"s try this. Sound has waves, right?
W: Right.
M: Well, we can describe these waves as in phase or out of phase with each other. "Out of phase" means reversed.
W: Uh-huh.
M: If you add two out-of-phase waves together at the same frequency, the result is antinoise—otherwise known as silence.
W: Antinoise is silence.
M: Right! And there"s a program that proves this. A microphone picks up the sound and sends it back to the computer, and then the computer reads the waves and makes sort of a mirror image, or a reverse copy of the wave. Then you can play it back against the original sound, and when the two waves meet, they sort of overlap each other, exactly at the high and low peaks. This eliminates the sound and creates zero sound: antinoise. It"s all in your textbook. Did you read the chapter on noise and antinoise?
W: No, I didn"t have time. I guess I have some catching up to do.
M: Yes, you do. Go read the chapter. But, you know, it"s better to do the reading every week before the lecture. You"ll have a better idea of what we cover in class.
W: Yes, I know. You"re right. I guess I"d better go do that. Thanks, professor. I appreciate your help.
M: You"re welcome. See you later.
What topics do the speakers discuss?
The speakers discuss how music differs from noise: I"m not sure I get what, what"s the difference between music and noise; ...bow"s a sound that"s noise different from a sound that"s music; Noise is different from music because it doesn"t have a pattern. They also discuss the meaning of antinoise: The other thing I don"t get is what you said about antinoise; Think of antinoise as the opposite of noise; ...the result is antinoise—otherwise known as silence.
单选题
According to the professor, what is noise?
【正确答案】
C
【答案解析】[听力原文]
According to the professor, what is noise?
The professor says Noise is a random sound. It"s a random sound that has irregular sound waves.
According to the professor, what is noise?
The professor says Noise is a random sound. It"s a random sound that has irregular sound waves.
单选题
Listen again to part of the conversation. Then answer the question.
Why does the professor say this:
Why does the professor say this:
【正确答案】
B
【答案解析】[听力原文]
Listen again to part of the conversation. Then answer the question.
"The other thing I don"t get is what you said about antinoise. I understand noise, but antinoise? I"m lost."
"Think of antinoise as the opposite of noise."
"I"m trying to, but it doesn"t make sense."
"It"s like...uh...wait, let"s try this. Sound has waves, right?"
Why does the professor say this:
"It"s like...uh...wait, let"s try this."
The professor"s purpose is to begin explaining the concept of antinoise. The student does not get (understand) what the professor said in the lecture about antinoise, so the professor starts to explain the concept.
Listen again to part of the conversation. Then answer the question.
"The other thing I don"t get is what you said about antinoise. I understand noise, but antinoise? I"m lost."
"Think of antinoise as the opposite of noise."
"I"m trying to, but it doesn"t make sense."
"It"s like...uh...wait, let"s try this. Sound has waves, right?"
Why does the professor say this:
"It"s like...uh...wait, let"s try this."
The professor"s purpose is to begin explaining the concept of antinoise. The student does not get (understand) what the professor said in the lecture about antinoise, so the professor starts to explain the concept.
单选题
How does the professor help the student understand antinoise?
【正确答案】
D
【答案解析】[听力原文]
How does the professor help the student understand antinoise?
The professor talks about a computer program that illustrates antinoise. He says And there"s a program that proves this. A microphone picks up the sound and sends it back to the computer, and then the computer reads the waves and makes sort of a mirror image, or a reverse copy of the wave; This eliminates the sound and creates zero sound: antinoise.
How does the professor help the student understand antinoise?
The professor talks about a computer program that illustrates antinoise. He says And there"s a program that proves this. A microphone picks up the sound and sends it back to the computer, and then the computer reads the waves and makes sort of a mirror image, or a reverse copy of the wave; This eliminates the sound and creates zero sound: antinoise.
单选题
After speaking with the professor, what will the student probably do?
【正确答案】
C
【答案解析】[听力原文]
After speaking with the professor, what will the student probably do?
The professor says Go read the chapter. But, you know, it"s better to do the reading every week before the lecture. The student says You"re right. I guess I"d better go do that. You can predict that she will complete the assigned reading.
After speaking with the professor, what will the student probably do?
The professor says Go read the chapter. But, you know, it"s better to do the reading every week before the lecture. The student says You"re right. I guess I"d better go do that. You can predict that she will complete the assigned reading.