ĐIỆN tử VIỄN THÔNG DTVT2 nhom1 bai7 khotailieu

NHÓM 1 – LỚP Đ8-ĐTVT 2
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HOÀNG NGỌC TRUNG
HOÀNG THỊ LINH
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PHẠM TRỌNG HOAN

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Lesson 7: Drum machine
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Task 1:
1. A drum machine imitate the sound of drums and percussion instruments
2. Closed hat and open hat, snare, kick are percussion instruments and Drum
machine imitate the sound of them
Task 2:
abcde-

c
e
b
a
d

Task 3:
Reading 1
a.
b.
c.
d.
e.
f.

analogue recording – paragraph: 2
what quantize means – paragraph: 6
the advantage of digital sound – paragraph: 4
what happens when one the drum buttuns is pressed – paragraph: 5
how sound samples samples are stored in a drum machine – paragraph: 3
in brief what the machine does – paragraph: 1

Reading 2
a. Changes in pressure of the air around us are what we hear as sound
Task 4:
1. By pressing the pads which corresspond to particular sounds, you can create your
own songs and rhythms withoout ever touching a drum kit.


2. The machine’s read- only memory (ROM) stores sounds which have been prerecorded from the original instruments.
3. When we hear sound, our ears are detecting changes in air pressure. These changes
in pressure , which might be caused by vibrating a guitar string or banging a
drum , are sound waves. To the record these, the wave patterns in the air are
converted by a microphone into electrical signals.
4. The voltage and frequency of these signals correspond exactly to the fluctuations

in pressure of the original wave
5. Measurements are taken at frequent regular intervals and then recorded as binary
code.
6. Sounds recorded in this way remain accurate.
7. When you press one of the drum pads, how hard you press and for how long, tells
the microprocessor how loud ang at which tempo the sound should be.
8. If you hit a note a little ahead or behind the beat, the machine will automatically
place the drum hit right on the beat.
Taks 5:
1.
2.
3.
4.
5.
6.
7.
8.
9.

With a drum machine, pressing the right button, you can play any drum sound
Without playing a drum, you can create drum music.
Changing the air perssure, what we hear as sound arc.
Using a microphone, these are converted to electrical signals.
Sampling the electtrical signals, the information contained in the drum machine
memory consists.
A drum machine contains recording of sound taken at measured intervals
This process is called sampling
The functions of a drum machine include panning and tuning
Panning means the positioning of the drum sound in stereo
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Task 6:
1.
2.
3.
4.
5.
6.

A burglar alarm = an alarm which warns of burglar
A clock timer = a clock which countdown time
A mercury swich = a swich which contains mercury
A car phone = a phone for use in a car
A germanium diode = a diode which contains germanium
A ground wave = a wave which travels along the ground, following the curvature
of the earth’s surface
7. A block diagram = a diagram which contains block
8. An assembly line = a line which assemblies complex item
9. A fuseholder = a device for protecting fuse


10. A wavemeter = an instrument for measuring wavelength
11. A cellphone = a device which receives and transfer signal
12. Headphone = a pair of small loudspeakers that are designed to be held in place
close to a user's ears
13. An ammeter = an instrument for measuring ampere
14. A handset = a device that a user holds to the hands
Task 7:
1. A sine wave an example of an analogue wave.
2. The magnitude of a digital signal has only two levels, high and low, which can be

represented by the binary digits 1 and 0 respectively
3. ADC is analogue-to-digital converter, the analogue signal can be changed into
digital signals.
4. The higher the frequency of the analoguesignal, the more often it must be sampled
5. A four-bit ADC has sixteen different binary values , the smallest value is 0000 and
the largest is 1111
An Eight-bit ADC has 256 different digital values
6. It will cause the analogue signal to suffer some distortion
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