공통영어1 미래엔 김성연 3과 변형문제

Which is the ____ environment for studying: a noisy place or a quiet place?

Rarely do people want to put up with a lot of noise because it can be unpleasant and ____.

Fortunately, scientists have ____ noise-cancelling technology, which is now being used across various fields to reduce unwanted noise.

What is the scientific principle ____ this achievement?

To ____ this, let’s examine how sound travels.

The ____ of Sound Waves and Interference

Sound is ____ through vibrations that occur from a sound source, when the strings of a guitar are played, for instance.

The vibrations of the sound source cause the air to vibrate and the sound to ____ as waves, similar to the ripples created in a lake when you throw a stone.

When ____ sound waves reach our ears, the brain interprets them as sound.

____ as different ripples in water might overlap if you throw two stones, sound waves can also interfere with each other when they meet.

____ are two types of interference: constructive and destructive.

____ interference occurs when the peaks of two waves overlap, resulting in a bigger wave and a louder sound.

____ interference, on the other hand, occurs when a peak of one wave overlaps with a valley of another wave, so they cancel each other out and produce a quieter sound, or no sound at all.

The ____ Behind Noise-Cancelling Headphones

____ interference is used in the noise-cancelling feature of headphones when we listen to music.

Inside the headphones are ____ and noise-cancelling circuitry.

The microphones pick up sounds from the outside, and the circuitry analyzes them to produce ____ sound waves.

For example, if ____ noise has a value of +1, the circuitry will generate an opposite noise of –1 and transmit it to the speakers.

This cancels out the unwanted sound even in noisy surroundings, so you can ____ the music sound clearly without turning up the volume.

However, it is ____ easy to entirely eliminate external noise with this technology.

To achieve full noise cancellation, the circuitry must convert the noise into digital data and ____ transmit the opposite sound to the speakers as soon as the noise reaches the microphones.

Therefore, this noise-cancellation technology is effective for predictable sounds like ____ of car engines and subways that occur regularly or over a period of time.

However, it’s relatively less ____ for inconsistent sounds such as those of people talking close to you.

____ technology is not only used in music devices.

Other fields also take advantage of this technology, such as ____ offices at tourist attractions which are often very noisy.

Microphones are installed in ticket offices to detect external noise, and an ____ sound wave is generated and transmitted through a speaker, enabling the ticket agent to hear the customer’s voice clearly.

Another area in which this technology is used is drive-through fast-food restaurants and ____ shops.

They use noise-cancelling headsets to improve communication between ____ and customers by eliminating vehicle noise.

These noise-cancelling headsets ____ drive-through employees take orders accurately.

The ____ technology is also used for cars, whose audio systems generate waves to cancel out unpleasant sounds such as engine, wind, and road noise.

Thanks to noise-cancelling ____, it is possible for drivers to focus on driving without being disturbed by distracting noises.

As technology advances, many people expect it will solve various social issues caused by ____ pollution.

A common source of these problems is ____ neighbors, as the noise they make can lead to conflict among residents.

Noise-cancellation technology can help address these problems by reducing unwanted disturbances, allowing ____ to lead more peaceful and healthier lives.