Page 94 - Genius Kidz Prudence Learning Sc-8

loudness. fundamental. While the mixture of sounds of

When a wire is struck in guitar it produces a other frequencies and varying loudness
basic sound of certain frequency called the produced simultaneously is called harmonics.

y
our
ed
b
recei
v
brain
and
v
is
of
a
kind
Sound
percei

sensation
y
or
b
detected
ears
ed
! ! Sound is a kind of sensation perceived by our brain and received or detected by our ears. .
! Sound is a kind of sensation perceived by our brain and received or detected by our ears.
our
Vibration
! ! Vibration produces sound.
produces
sound.
! Vibration produces sound.
oice
! Adam's apple or voice box in human is the sound producing organ.
v
x
bo
! ! Adam's apple or voice box in human is the sound producing organ.
producing
an.
org
sound
or
apple
the
human
in
is
Adam's
! Ear is the sound detector organ.
detector
sound
an.
the
is
org
! ! Ear is the sound detector organ.
Ear
tra
solids
and
liquids
el
through
,
v
.
air
Sound
can
! Sound can travel through air, liquids and solids.
! ! Sound can travel through air, liquids and solids.
de
Sound
! ! Sound loudness depends on amplitude of vibrations.
! Sound loudness depends on amplitude of vibrations.
on
loudness
of
pends

vibrations
amplitude
.
! ! Sound pitch depends on frequency of vibrations. .
on
Sound

vibrations
of
frequency
! Sound pitch depends on frequency of vibrations.
pends
pitc
de
h
a
is
ho
! An echo is a reflected sound.
! ! An echo is a reflected sound.
An
ref
ec
sound.
lected
types
String
percussion.
ed,
wind,
instr
:

three
of
are
Musical
uments
! ! Musical instruments are of three types : Stringed, wind, percussion.
! Musical instruments are of three types : Stringed, wind, percussion.

of
surfaces
better
! ! Soft surfaces are better absorbers while hard surfaces are better reflectors of sound.
ref
are
sound.
lectors
! Soft surfaces are better absorbers while hard surfaces are better reflectors of sound.
Soft
absorbers
while
are
surfaces
better
hard
EXERCISE
EXERCISE
1. Multiple choice questions.
(a) Sound cannot propagate through:
(i) liquid (ii) solid (iii) air (iv) vacuum
(b) 65 dB is the sound which is produced by:
(i) violin (ii) speaking (iii) rock music (iv) soft music
(c) Higher pitch is of a :
(i) lady (ii) man (iii) dog's bark (iv) lion roar.
(d) Sound travels the fastest in :
(i) Air (ii) Water (iii) Vacuum (iv) Solids
2. Fill in the blanks.
(a) __________________ produces sound.
(b) __________________ is the process of sound production by quasi - periodic vibrations of the
vocal cords of larynx.
(c) Ear canal transmits the sound to __________________ .
3. Match the columns.
Column A Column B
(a) Sound (i) 20 to 20,000 Hz
(b) Audible sound (ii) Shrill voice
(c) Pitch (iii) Heavy voice
(d) Man (iv) dB
(e) Inner ear (v) Nerve cell vibrations
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