Buku Scrap science form 2

7/27/2019 Buku Scrap science form 2

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TECHNOLOGICAL DEVICES FOR

OVERCOMING THE LIMITATIONS

OF SIGHT AND HEARING

NAME : NOR ATIQAH MOHD CHOLIF

CLASS : 2 BESTARI

IC. NO : 990423018372

TEACHER’S NAME : MR. SHUKRY AWAP

SCHOOL : SMK TUANKU ABDUL RAHMAN



INTRODUCTION

Welcome to my scrap book entitles Technology devices for overcoming the

limitations of sight and hearing . Humans have sight and hearing limitations . Limitations of

sight can be overcome by using appropriate optical devices such as microscope . The range of

frequency of hearing and human is from 20 Hz – 20 000 Hz and it is different according to the

age of the person . We can overcome hearing and sight limitations by using appropriate

technological devices .



LIMITATION OF SIGHT

- Sometimes the brain cannot accurately interpret what is actually seen by the eye .

- This limitation of the sense of sight is known as optical illusion ( confusion of the

brain ) .

- The blind spot is point on the retina of the eye that cannot detect any images .

- The blind spot does not have any receptors sensitive to light and is found at the

beginning of the optic nerve .

- We cannot see an object if its image is formed on the blind spot .

1- MICROSCOPE

- An instrument used to see objects that are too small for naked eye .

- The first microscope invented by Zacharias Janssen .

- Magnify small organism such as fungi , bacteria , virus and all others organism which

can’t be seen with naked eyes .



2- TELESCOPE

- A telescope is an instrument that aids in observation of remote objects by collecting

electromagnetic radiation ( such as visible light ).

- The main function of the telescope is see far objects in the universe such as moon .

3- BINOCULAR

- Binoculars , field glasses or binocular telescopes are a pair of identical or mirror -

symmetrical telescopes mounted side-by-side and aligned to point accurately in the

same direction , allowing the viewer to use both eyes ( binocular vision ) whenviewing distant objects .



4- PERISCOPE

- A periscope is an instrument for observation from a concealted position .

- In its simplest form it consists of an outer case with mirrors at each and set parallel to

each other at a 45 degree angle .

- More complex periscope , using prisms instead of mirrors and providing

magnification , operate on submarines .

5- ULTRASOUND MACHINE

- Ultrasound is an oscillating sound pressure wave with a frequency greater than the

upper limit of the human hearing range .



- Ultrasonics is the application of ultrasound . Ultrasound can be used for medical

imaging , detection , measurement and cleaning .

6- MAGNIFYING GLASS

- A magnifying glass ( called a hard lens in laboratorycontexts ) is a convex lens is used

to produce a magnified image of an object .

- The magnification of a magnifying glass depends upon where it is placed between the

user’s eye and the object being viewed and the total distance between them .



LIMITATION OF HEARING

- A person with normal sense of hearing can only detect sounds between 20 Hz and 20

000 Hz (hertz ) .

- Different people have different ranges of hearing . As we grow older , our range of

hearing decreases .

- There is also a limit to how far our ear is able to hear sounds from a distance .

- We also cannot hear very soft sound like our heartbeat .

- The limitations of hearing can be overcome by using hearing aids .

1- MICROPHONE

- A microphone is an acoustic-to-eletric translucer or sensor that converts sound into an

electrical signal .

- Microphones are used in many applications such as telephones , tape recorders ,

karaoke systems , hearing aids , motion picture production , live and recorded audio

and engineering , FRS radios , megaphones , in radio and television broadcasting and

in computers for recording voice , speech recognition , VolP and for non-acoustic

purposes such as ultrasonic checking or knock sensors .



2- HEARING AIDS

- A hearing aid is an electroacoustic device which typically fits in or behind the

wearer’s ear and is designed to amplify and modulate sound for the wearer .

- Similar devices include the bone anchored hearing aid and cochlear implant .

3- STETHOSCOPE

- The stethoscope is an acoustic medical device for auscultation or listening to the

internal sounds of an animal or human body .

- It is often used to listen to lung and heart sounds .



4- LOUDSPEAKER

- A loudspeaker (or “speaker” ) is an electroacoustic transducer that produces sound in

response to an electrical audio signal input .

- Non-electrical loudspeakers were developed as accessories to telephone systems , but

electronic amplification by vacuum tube made loudspeakers more generally useful .

5- EARPHONE/ HEADPHONE



- Headphones are a pair of small loudspeakers that are designed to be held in place close

to a user’s ears .

- Headphones either have wires for connection to a signal source such as an audio

amplifier , radio , CD player , portable media player or mobile phone , or have a

wireless receiver , which is used to pick up signal without using a cable .

CONCLUSION

All humans have sight and hearing limitations . So , there are technology devices to

overcome all the limitations . Thank you ....

Buku Scrap science form 2

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