1. REPORT
Sound
Many people and animals rely on sounds to communicate with each other. Unforeseen or
unanticipated sounds may warn people of danger in any given circumstances. The sounds
and noises that we hear every day tell us a lot about our surroundings, including where we
are and what is happening around us. The sounds and noises that we hear are vibrations
which move through the air or materials which then in turn can be heard when the sound is
reflected onto the ear drums.
Sound can be described as a wave, similar to hearing a lightning strike in the far distance,
our sound waves are very sensitive. This wave of sounds will inform you that you have heard
a loud noise or bang in the distance.
Sound waves are measured in decibels (DB). Vibrations are caused by our voice boxes,
speakers, nature, objects etc.
Acoustics
A way to describe acoustics would be the science behind sound. It is a part of physics that
concentrates on the study of sounds this includes the mechanical waves in gases, liquids as
well as solids. The study of acoustics also include the production, transmission, control,
reception and effects of sound in our everyday lives.
There are certain things that affect how sounds is transmitted, for example the properties of
a room or a building will determine what type of sounds is spread inside.
You can find acoustics in any hard surface which is able to reflect sound. The time it takes
for the sound to die out is called the reverb time– this occurs through prolonging the sound
onto every hard surface in a specific environment until the energy in the sound fades.
The application of acoustics can be seen in almost all aspects of society with mainly in the
audio and noise control industries.
Microphones
Microphones aid artists during their performances. Microphones are difficult to damage and
are also very expensive. There are various types of microphones such as handheld, livelier,
direct connected, boundary microphone, parabolic and an inside the microphone.
Microphones work through having a small plastic layer called the diaphragm. The diaphragm
is attached to a coil which is also attached to a magnet. When an artist sings/speaks into
the microphone, the sounds hits the diaphragm and the energy/vibrations is passed through
to the coil.
2. Dynamic
Dynamic microphones are microphones that change sound into an electrical signal through
electromagnetism. There are two types- moving coil and ribbon microphones.
In a moving coil microphone the coil is glued to the back of a membrane, and there is also a
strong magnet surrounding the coil. When sound waves hit the microphone, the membrane
moves to the rhythm of the sound waves that hit the microphone, and in turn the coil
moves along with it. The movement of the coil within its magnetic gap prompts a small
signal voltage. Moving coil microphones are usually used on stage.
Instead of having a membrane and a coil, a ribbon microphone uses a narrow strip of
particularly thin aluminium foil. Which means that the membrane itself is the electrical
conductor which moves inside the magnetic gap. The thin piece of aluminium ribbon is
much lighter than a membrane with a coil of copper. This means that the ribbon
microphone is able to follow the exact movements of the sound waves, more accurately
than a moving coil microphone.
Condenser:
The term Condenser means capacitor, which is an electronic component that stores energy
in the form of an electrostatic field. The word condenser is the name used for a certain type
of microphone, a condenser microphone uses a capacitor to transform acoustical energy
into electrical energy.
Condenser microphones need power from a battery or external source to work. The audio
signal produced from a condenser microphone is a much more stronger signal than the
signal produced from a dynamic microphone.
Condensers are also more sensitive and responsive
than dynamics, making them suited to capturing
subtle nuances in any sound. However their
weakness is that they are not the best option for
high-volume work, as their sensitivity makes them
susceptible to distort sounds.
3. Characteristics
Sound can be categorised by the following three quantities:
Pitch
Quality
Loudness
Pitch is the frequency of a sound as heard by the human ear. A high frequency creates a
high pitch for example the frequency created by a tuning fork or electronic signal generator.
The fundamental note has the highest amplitude and is mostly heard because it is more
intense. The other various frequencies such as 2fo, 3fo, 4fo - are called overtones or
harmonics and they determine the quality of the sound.
Loudness is a physiological. Therefore it depends mainly on sound pressure but also on the
spectrum of the harmonics and the physical duration.
The Proximity Effect.
The proximity effect leads to an increase in low frequency response when the microphone is
moved closer to the source of sound. The closer the sound to the microphone the higher the
bass boost.
Cables
The term often describes the wires with mini-phone plugs at both ends for transferring
analogue sound from a computer or music player to a set of speakers.
Devices
Sound devices are a means used by poets to convey and reinforce the meaning or
experience of poetry through the skilful use of sound.
