Acoustic Flashcards
(15 cards)
Definition of sound?
Vibrations that travel through the air or another medium and can be heard when they reach the ear.
Definition of noise
Sound that is unwanted by the recipient.
how is sound is created
by vibrating an object creating a pressure wave
Longitudinal waves travel in ?
compressions and rarefactions.
The physical properties of sound are?
frequency and sound pressure
What frequency can be tolerated at greater sound pressures?
Low frequency noise can be tolerated at greater sound pressure levels that high frequency.
The main factors of room acoustics are?
Volume of the room, the arrangement of the audience and the materials in the room.
What are the two different types of sound received?
Direct sound and reflective sound.
Background noise is?
The total of all sounds in a room when it is unoccupied.
SNR (signal to noise ratio) is?
the difference between the total background noise and the level of sound a person can hear. This should equal or exceed 15dB.
The three methods for noise control are:
Control noise at source. Control noise along transmission path. Control noise at receiver.
The two types of sound transmission are?
Airborne and impact.
What materials have high reflection and low absorption.
Hard & heavy materials
what materials have low reflection and high absorption.
Soft & light materials
The absorption coefficient of a material is?
A number between 0 and 1. This is a rating of how much sound a material / surface can absorb.
