Sound Engineering

Question 1

Explain the concept of light

Answer 1

Light is the visible part of the electromagnetic spectrum. It is a small part of the electromagnetic spectrum.

Question 2

Explain the concept of sound

Answer 2

Sound is vibrations within the air. We are able to perceive sound in the frequency range of 40 to 40000 hertz. Or vibrations per second.

Question 3

What factors affect the sizing of hvac plant.

Answer 3

External air temperature. Humidity, exposure or average wind velocity. Solar irradiance, rainfall, pollution.

Question 4

What factors affect sound transmission through a partition?

Answer 4

Thickness and density of the partition. Insulation. Surface area of the partition. Sound absorption in the receiving room. Frequency of the sound source (high frequencies are easier to block than low frequencies). Intensity of the sound source (volume). Angle of incidence of the sound wave.

Question 5

What sort of partition would make an excellent sound barrier

Answer 5

Two layers of concrete with an airgap in between

Question 6

What is insertion loss

Answer 6

It is the decibel reduction from including a new attenuating device like a duct silencer. It is a simple arithmetic subtraction of decibels. this can only be specific to an installation.

Question 7

Define noise control

Answer 7

Reducing sound transmission by active or passive means. It is important to understand the sources, the nature (frequency, volume, intermittency) and the transmission paths of the noise.

Question 8

What are the common noise sources

Answer 8

Areodynamic, fluid dynamic and mechanical.

Question 9

What are the four physical methods of noise control?

Answer 9

Absorption, sound insulation, vibration damping of structure born noise. Vibration isolation.

Question 10

What are is priority order of noise control

Answer 10

Noise control at source,
Noise control along the sound path,
Noise control at the receiver,