STRUCTURE BORNE

&

AIR BORNE SOUND

NAME MATRIC NO.

RACHAEL JOHN LEONARDI 08DPB12F1063

TAN YEE TEAN 08DPB12F1043

HO Y NAM 08DPB12F1081

THAVEN 08DPB11F2040

DEFINITION :

Structure Borne Sound is the sound which spreads in

solid bodies such as walls of houses, heaters, pipes, etc.

Transmission occurs particularly by tremors which are

conducted by vibrations.

DEFINITION :

Air Borne Sound is ultimately the sound which can

spread only via the air. This can be detected, at

least by the human ear, from 20Hz - 20000Hz.

Common cause: Structure-borne noise:

• Is the sound generated from a vibrating source

/impact event.

• The acoustic energy created by these vibrations is

transmitted into the structure of a building (e.g.

floors, walls, pipe-work etc.) or into mechanical

elements (e.g. metal frames, panel work, supports

etc.)

• This energy travels through solid structures and

released as air-borne noise at different locations

within the building or mechanical system.

acoustic energy

Sound created by Vibration (knocking table)

Example: Knocking the Table

Transmitted into the table

Released as Air Borne Noise/Sound

Structure-borne noise:

Common cause:

Air-borne Sound:

• Is the sound that travels through the air and into

the surrounding environment.

• In closed environments such as rooms and

enclosures, air-borne sound may reverberate

(echo) and increase the levels of noise both in and

outside the contained space.

The TRANSMISSION of acoustic energy

through a medium via a SOUND WAVE.

SOUND PROPAGATION :

Factors which affect the propagation of sound:

1. Geometric Spreading

2. Atmospheric Effects:(a) Air Absorption

(b) Wind & Temp. Gradient

3. Surface Effects: (a) Ground Absorption

(b)Attenuation(reduction) Due to Barriers and Trees:

SOUND PROPAGATION :

METHODREDUCE

Reduction at theReceiver End

Reduction of theTransmission Path

Reduction atNoise Source

Noise Barrier

Noise absorber

Reducing Effect of vibration caused by Building Services Equipment:

• Damper can be used to reduce vibration from A/C

condenser (outdoor unit).

• Noise Barrier can applied on anywhere for purposed to

block the noise sound caused by vibration.

• Sound absorption materials can be used to

eliminated/absorbed the vibration that cause by the

B.S equipment.

THANK YOU !!