This document discusses different types of microphones used to capture sound waves, including carbon microphones, ribbon microphones, and lavalier microphones. Carbon microphones were the first design and work by converting sound vibrations into electrical signals using carbon plates. Ribbon microphones use a vibrating metal ribbon in a magnetic field to induce electrical currents. Lavalier microphones are small clip-on microphones that allow for hands-free operation and are commonly used for television and public speaking. The document compares the advantages and disadvantages of each microphone type.

1. Name: Nawal Ali Abdelsalam
College of Electronic Technology-Bani Walid
Department of IT & Computer Engineering
Devices to Capture Sound WavesDevices to Capture Sound Waves
Prepared By:

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Introduction
A microphone is a device known as a type of transducer that
coverts an audio signal into a electrical voltage. The sensitivity
of the microphone and the way this process happens
differentiates between different microphone types.
When choosing a microphone you should consider the
characteristics and the properties of a microphone to get the best
possible recording.
Some microphones are built for a purpose while others are built
for a more general use; this is why care should be taken when
opting for a microphone.
There are many microphone types such as (Carbon microphone,
Ribbon microphone, Lavalier microphone.

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Carbon Microphone:
The first microphone design.
A carbon microphone is built inside a tube. It consists of two metal
plates with a layer of small grains of carbon between. Each metal
plate is attached to a wire which connects it to an audio receiver.
The top of the microphone is usually covered with a metal or
plastic sheet with holes in it, which lets sound in while preventing
anything from damaging the microphone element.

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Carbon is a resistor, meaning it conducts electricity, but not
very well. A current runs from one plate through the carbon to
the other plate. The carbon molecules normally resist it
somewhat, lowering the power flow. When a sound wave
pushes down on the top plate, however, it squeezes the carbon
molecules more tightly between the two plates. This increases
their conductivity, creating more electric current. As the plate
moves up and down with the sound wave, the current increases
and decreases, creating an electric wave in the shape of the
sound wave.

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Carbon microphone applications:-
Carbon microphones were an ideal choice
of microphone in the early days of the
telephone. They were widely used in
telephone applications because they gave
a high output which meant no
amplification was used.
The carbon microphone was used for telephones up until the
1970s and 1980s.
Carbon microphones are now only used in a very few
applications – typically only specialist applications.

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 High output.
 Simple principle & construction.
 Cheap and simple to manufacture.
 Very noisy.
 Poor frequency response.
 Requires battery or other supply for operation.
Carbon of microphone disadvantages-:
Carbon of microphone advantages-:

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Ribbon Microphone:
A ribbon microphone uses a corrugated ribbon made
of a metal is suspended in a magnetic field.
Sound causes the ribbon to vibrate. This means
change in magnetic flux through the ribbon. This
induces an electric current which drives a speaker.
When this current is flown through a coil attaches to
diaphragm of the microphone, the diaphragm vibrates
and produces sound. Special materials developed
using nano technologies are being used to make
ribbons that will be light but strong. Being light
improves the response to sound. The ribbon
microphone senses pressure gradient and not just
pressure. Therefore, it detects sound from both sides.

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Advantages of ribbon Microphone:-
 Good response for musical instrument.
 Ideal for dramas.
 Does not require an external bias.
Disadvantages of ribbon Microphone:-
 It is very fragile and dielectric.
 Continuity and the resistance of the ribbon cannot be measured
using metallic.
 Any mechanical shock can displace the ribbon.

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LavalierorLapel Microphone:
A lavalier microphone or lavalier (also
known as a lav, lapel mic, clip mic, body
mic, collar mic, neck mic or personal mic)
is a small microphone used for television,
theatre, and public speaking applications
in order to allow for hands-free operation.
They are most commonly provided with
small clips for attaching to collars, ties, or
other clothing. The cord may be hidden by
clothes and either run to a radio frequency
transmitter kept in a pocket or clipped to a
belt, or a recording device.

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 Greater freedom of movement for the speaker.
 Almost unnoticeable on garment.
 Good quality of voice transmission.
 One of the best solutions for TV, Video, YouTube,
broadcasters.
Advantages of Lavalier Microphone:-
Disadvantages of Lavalier Microphone:-
 It is no good for studio session.