Listening and speaking

Task 1. Read this newspaper article: High-tech mystery

High-tech machines leave many owners baffled, according to a survey by electrical retailers. Nearly a third of those with video recorders and 57 per cent of camcorder owners do not use all the functions. The 16-24 age group understood the technology best, with 70 per cent saying they were the family expert.

A recent survey of video owners found that over 70% could not set their timers

Survey your group. Ask these questions:

1 Does your family have a VCR?

2 What is it used for?

3 Who knows how to set the timer?

4 Does your family have a camcorder?

5 What functions are not used?

Task 2. You are going to hear a short talk. The speaker will explain some of the

differences between conventional audio and video recording. Before you listen, note down any differences you already know.

Task 3. Now listen and complete this table to show some of the differences between audio and video recording.

Audio Video

Medium magnetic tape magnetic tape

Tape width 1/4 inch

Type of heads

Speed (cm/sec) 2.339 (VHS)

Scanning linear

Data recorded in 1 sec. 2 5 complete separate pictures

Task 4.Read this text and match each change in VCR design with its result, as in the example below.

The step from recording sound on magnetic tape to doing the same with video signals is one of increased band width. Early reel-to-reel machines used one-inch wide tape and made the most of the available band width by moving the tape past the head at high speed. Unfortunately, this meant that the transport mechanism had to be built to a high specification.

Improvements in magnetic tape and the use of helical scanning meant that far more data could be crammed into a smaller area. By spinning the head at a high speed, the rate at which the data could be stored or retrieved was increased. Aligning the head at an angle to the tape laid down the information as a series of slanted tracks. This allowed the cassette tape to be narrower and move at a slower speed, giving rise to the modern video cassette recorder.

Early VCRs were playback-only, but by building in a full-colour TV tuner, programmes could be recorded from the air while another channel was being viewed on a normal TV. The inclusion of a timer meant that recordings could be made and viewed at a later date. Early timers only switched the tape on at a certain time, leaving the VCR running until the tape finished. The latest machines allow a large number of on/off programmed times to be set so that viewers can go on holiday and not miss a single episode of their favourite soap opera.