English for AVT specialists. Английский для специалистов в сфере аудиовизуальных технологий. Сборник текстов и упражнений по английскому языку - страница 12

Grammar revision: active and passive voice

We use the active voice to say what the subject of the sentence does:

In the 1970s, Dolby professionals made an introduction of a separate «boom» subwoofer channel, or so called the «LFE channel».

We use the passive voice to say that something happens to the subject:

However, mastering these technologies was limited by certain economic factors.

Here is some more information about the passive voice.

We use a passive verb

1) when what or who causes the action is unimportant, unknown or obvious from the context:

Two new studios have been built recently.

2) to sound more formal or more polite:

The letter hasn’t been sent. (Instead of: You haven’t sent the mail.)

3) when the action itself is more important than who or what does it (in technological processes, reports, newspaper headings, manuals, instructions, regulations etc.):

Dolby Stereo Digital was first encoded on the 1992 film Batman Returns.

4) to put more emphasis on the agent:

The new laboratory will be opened by the company president.

We form the passive voice with the verb to be and the past participle of the main verb:

be (is/was/have been etc.) + the past participle (made/ washed/done etc.)

10. Fill the gaps in the sentences with the verbs given. Use them in the correct tense either in the active or in passive voice.

Remain, influence, introduce, limit, evolve, fail, beset, receive, increase.

1) Some of these technological advances finally _______ into meaningful improvements.

2) The cinematic systems of that time were unable to produce loud low frequency signals without clipping, that’s why a subwoofer channel (also called the «LFE channel») _____ ______ by Dolby Laboratories.

3) Though the pioneering idea of the Quad installation______, it led to further exploration into consumer surround sound.

4) The acceptance of new technologies, especially since the expansion of television was making serious inroads into the profit margins of the cinematograph, _____ ______ by certain economic factors.

5) Until the early 1950s the dominance of the movie was obvious and it _______ the main source of public entertainment.

6) By the late 1970s, specialists at Dolby Laboratories started their development of the Dolby Stereo system, whereby information _____ _____ by three front speakers and a few rear speakers.