EngМетодВказ2курс

3.Provided you are moving away from the source, the sound pressure level

_____. (to drop)

4.Even a measurement microphone ____ the sound field if the wavelength is 3,4 cm. (to disturb)

5.What _____ when sound is propagating through a medium which does not have constant properties? ( to happen)

6.At the frequency is 100 Hz sound insulation_____ rather difficult. (to become)

7.Suppose sound is propagating over ground, attenuation ______ due to acoustic energy losses on reflection. (to occur)

8.How much sound is reflected _____ on such properties of the object as its size. (to depend)

9.In sound propagating smooth hard surfaces _____ little absorption. (to produce)

10.In the case of a line sound source cylindrical spreading _______(to be produced).

II. Complete the sentences with one of the words:

1.The further from the sound source, the _____ the oscillations amplitude. litle

less least

2.Any measurements in the near-field of the machine are _____ avoided. possible

possibly possibility

3.The object _____ than one wavelength doesn’t result in substantial disturbance of sound.

small

smaller

smallest

4 Sound insulation can be reached _____ if there is a large obstacle in the sound path.

ready readier readily

5 Being too close to the machine we can observe very ____ variation with a small change in sound level meter position.

significant significantly significance

6.This motion propagates to the next particle, then the next particle, and so

____.. on

so as

7.The oceans are largely transparent to sound, ______signal processing acoustic techniques are primary tools for ocean observation and engineering.

but however hence

8. ______Like ripples on a pond sound waves propagate in air uniformly in all directions away from the source.

like likely alike

9. Will sound _______ travel in solids faster than in gases?. mostly

generally mainly

10. If atmospheric sound propagates _______ to the ground it is sensitive to the acoustical properties of the ground surface as well as to meteorological conditions.

almost nearby close

Word-Building

I. Translate the sentenses paying attention to the mening of the prefix .

«trans» adds «across» or «beyond» to the meaning of a word.

1.The process of moral transvaluation is essentially a a step back from the socially constructed systems of value to look at the larger picture.

2.Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body,

3.To transliterate means to represent letters or words in the corresponding characters of another alphabet.

4.To transfix means to pierce with pointed weapon.

5.If we think of transfiguration as a chemical reaction the atoms of the first matter would simply be rearranged in order to produce the molecules of the intended matter.

6.The Transpacific Yacht Race starts near Los Angeles and ends in Honolulu.

7.Different proteins were identified through combined analysis of their translocation time, volume, charge and shape.

8.The company accepts no liability for any claims arising from any failure to complete a transaction.

9.Transmarine plants have adaptet to our climate.

10.Engineering design and analysis is replete with examples of mathematical transforms.

II. Form the nouns from the following verbs using suffixes –er, -or, -ent, -ant.

to study, to collect, to teach, to assist, to drive, to resist, to constitute, to attend, to

visit, to operate.

Scientific Communication

I.Translate the text in which sound pressure level is described without using a dictionary. Make up a dialogue using the previous text.

Sound pressure or acoustic pressure is the local pressure deviation from the

average atmospheric pressure caused by a sound wave. Sound pressure in air can be measured using a microphone, and in water using a hydrophone. The unit for sound pressure is the pascal (Pa).

Sound pressure level is a logarithmic measure of the effective sound pressure of a sound relative to a reference value. It is measured in decibels (dB) above a standard reference level.

II. Make a report about sound pressure level measurement.

Unit 2

I. Memorize the following words:

angle – кут

bounce – відскакувати, рикошетувати boundary – межа

cathedral – собор

chamber – зал, порожнина, робочий простір concave – увігнутий

curve – вигинати entrance – вхід depth – глибина incidence – падіння plane – площина ray – промінь straight – прямий

surface – поверхня

whisper – шепотіти.

II. Work in pairs. Ask your partner the following questions:

1.What is echo caused by?

2.Where can we deal with echo?

3.Is there any difference between indoor and outdoor hearing?

4.Does sound have the same properties as light?

5.Do sound waves travel on space like light waves?

6.What is ultrasonic diagnostics based on?

7.How does depth measurement occur?

8.How does radar work?

9.What is the ray angle of incidence on surface equal to?

10.Could you give some examples of waves reflections?

III. Scan through the text and find out the words which mean:

1.the large entrance room of a house or building

2.the figure formed by two rays

3.any of the thin lines of light that appear to come from a bright source

4.a surface capable of reflecting light to form an image of an object placed in front of it.

5.the point of origin

6.the outer boundary of an object

7.the organ of hearing

8.a large important church

9.a point at which rays converge or from which they appear to diverge

10.a disturbance on the surface of a liquid body, as the sea or a lake

III. Translate the text into Ukrainian.

Reflection

Like light wave sound waves are reflected from a plane surfaces so that the angle of incidence is equal to the angle of reflection. Besides, the incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence

lie in the same plane. The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal. Sound waves proved to come to a focus when they are incident on a curved concave mirror. A surface shaped like a parabola reflects sound waves to long distances in a straight line, the source of sound being placed at its focus. Many stages are designed as parabolas so the sound will go directly into the audience, instead of bouncing around on stage. If the parabola is closed off by another curved surface, it is called an ellipse. Sound will travel from one focus to the other, no matter where it strikes the wall. The famous whispering gallery at St. Paul's Cathedral is an ellipse-shaped chamber whose walls repeatedly reflect sound waves round the gallery, so that a person talking quietly at one end can be heard distinctly at the other end. Reflection is responsible for many interesting phenomena. Echoes are the sound of your own voice reflecting back to your ears. The sound you hear in an auditorium after the bell has stopped ringing is caused by reflection off the walls and other objects. A sound wave will continue to bounce around a room, or reverberate, until it has lost all its energy. A wave has some of its energy absorbed by the objects it hits. The rest is lost as heat energy.

We know reflection to be the change in direction of sound or radio wave on meeting a large surface. There is a fundamental difference between hearing sounds in the open and hearing them in a hall. In the open the sound reaches the listener by but one path, where as in a hall multiple reflections take place from the walls so that the sounds arrive by many paths. The design of a hall involves making good use of multiple reflections while avoiding certain unpleasant effects.

Vocabulary, Comprehension and Summary Writing

I. Answer the following questions to check your understanding of the text:

1.What is the angle which the reflected ray makes to the normal equal to?

2.What happens when a sound wave hits a concave shaped mirror?

3.Why are a lot of stages shaped like a parabola?

4.How does sound travel inside ellipse-shaped chamber?

5.How does sound reach listener in the open?

6.How are sound reflections from the wall used by designers?

7.What will happen if a radio wave meets a large surface?

8.Why do we hear sound ringing in an auditorium after the band has stopped playing?

9.What is the whispering gallery at St. Paul's Cathedral famous for?

10.Is the energy of sound wave lost completely because the objects it hits absorb it?

II. Agree or disagree with the following statements:

1.The incident ray and the normal to the reflection surface at the point of the incidence lie in different planes.

2.If the source of sound is placed at the focus of a surface shaped like a parabola it reflects sound waves to long distances.

3.In a hall the sound reaches the listener by but one path without any reflection from the walls.

4.Usually multiple reflections cause only unpleasant effects.

5.A person talking loudly at one end of ellipse-shaped gallery can’t be heard at the other end.

6.The sound of your own voice reflecting back to your ears is called echo.

7.On hitting the object a sound wave loses a part of energy.

8.Being in an auditorium you still hear the bell ringing after it stopped.

9.On meeting a surface a radio waves never change their direction.

10.If sound waves are incident on a curved concave mirror they converge to its focus.

III. Fill in the gaps with the following words and word combinations.

boundary, focused, angle, observer, parabola, straight, whispering, frequency,

sound intensity, depth

1.The ______ is the product of the sound pressure and the particle velocity.

2.You can refer to someone who sees or notices something as an ______.

3.In ______ articulation remains the same as in normal speech.

4.The water ______ in the field makes up 2 meters

5.This equation is used until some previously decided upon upper ______ is reached.

6.The coordinate of the current point of the ______ line yz along O1X1 is x1.

7.Note that audible sound has a very wide ______ range.

8.Sound waves can be reflected as a ______ beam.

9.A ______ may be considered an ellipse that has one focus at infinity.

10.The detail can be fixed on the device at any ______.

Grammar Structure in Scientific English

I. Put the verbs in brackets in the right form.

1.If he ________ (to carry out) the experiment correctly the results would have been quite different.

2.If two notes ________ (to recognize) by ear to be of the same pitch their sources are making the same number of vibrations per second.

3.Were the plate potential made negative, the electrons ________ (to be repelled) and little or no current would flow.

4.If the turning between the two waves _______ (to be) very close, it would be difficult to read the signal.

5.The ultrasonic cleaner, if it _______ (to be) necessary, can be operated in a cold room.

6.If a sound source and two microphones are arranged in a straight line, with the sound source at one end, then the time of arrival between the signals ________

(to reach) the different microphones can be measured.

7.If the wire potential is negative with respect to cathode potential, then the number of electrons _______ (to hit) the wire will be very small.

8.Suppose you _______ (to watch) TV and have the volume set you shouldn't bother others who are sleeping.

9.If the room you're working in ________ (have) poor acoustics, it will be extremely difficult to produce excellent results.

10.If the grid is sufficiently negative the beam will be cut off, so that by _______

(to vary) the grid potential a brilliancy control is achieved.

II. Complete the sentences with one of the words:

1.There aren't ___ books on this topic in the room. any

some no

2.I have ___ dictionaries in my library that you are welcome to use. any

some no

3.We are taking a short walk. There's ___ time for a long one. any

some no

4.The students haven't asked the lecturer ___ questions so far. any

some no

5.Don't you know the proverb: “___news is good news”?. any

some no

6.The pressure changed, so ___ the temperature.

was

is

did

7.Some aspects of the system design present problems similar to ___ found earlier.

ones those that

8.The toughest requirements are for diagnostic systems. For monitors ___ are not so strict.

ones those these

9.___ can measure very small input signal with ECG machines.

one

it

that