These illustrations of Noise and Vibration Control Principles and Application were developed by Stig Ingemansson, Ingemansson Technology, Gothenburg, Sweden. After his death, his company released the illustrations to the public domain to benefit noise control goals in the larger community.

View Entire Ingemansson Graphics document (.pdf file)

	A1	Sound Behavior - Causes of sound production Changes in force, pressure, or speed produce noise
	A2	Sound Behavior - Causes of sound production Airborne sound is usually produced by vibration in solids and fluids
	A3	Sound Behavior - Causes of sound production Structureborne sound travels great distances
	A4	Sound Behavior - Low and high frequencies The rate of change determines the amount of high frequency noise
	A5	Sound Behavior - Low and high frequencies The slower the repetitions, the lower the frequencies of the noise
	A6	Sound Behavior - Low and high frequencies High frequency sound is highly directional and easy to reflect
	A7	Sound Behavior - Reduction in air High frequency sound is greatly reduced by passing through air
	A8	Sound Behavior - How disturbing? Low frequency noise is less disturbing
	B1	Sound from vibrating plates - Size and thickness Make vibrating surfaces as small as possible
	B2	Sound from vibrating plates - Size and thickness Densely perforated plates produce less noise
	B3	Sound from vibrating plates - Size and thickness A long, narrow plate produces less sound than a square one
	B4	Sound from vibrating plates - Size and thickness Plates with free edges produce less low frequency noise
	B5	Sound from vibrating plates - Size and thickness Light objects and low speed produce the least impact noise
	B6	Sound from vibrating plates - Size and thickness A damped surface produces less sound
	B7	Sound from vibrating plates - Resonance Resonance amplifies noise but it can be damped
	B8	Sound from vibrating plates - Resonance Resonance shifted to higher frequency is more easily damped
	C1	Sound production in air or gases - Wind tones Wind tones can be eliminated
	C2	Sound production in air or gases - Wind tones Air flow past hollow openings should be avoided
	C3	Sound production in air or gases - Ducts Ducts without obstructions produce the least amount of noise from turbulence
	C4	Sound production in air or gases - Ducts Undisturbed flow produces the least amount of exit noise
	C5	Sound production in air or gases - Ducts Jet noise can be reduced by using an extra air stream
	C6	Sound production in air or gases - Ducts Low frequency jet noise is easier to reduce if converted to high frequency
	C7	Sound production in air or gases - Fans Fans make less noise if placed in smooth, undisturbed flow streams
	D1	Sound production in flowing liquids - Pipe systems Abrupt changes in area produce noise
	D2	Sound production in flowing liquids - Pipe systems Large and rapid changes in pressure produce cavitation noise
	E1	Sound propagation indoors - Placement of sound source Sound sources should not be placed near corners
	E2	Sound propagation indoors - Absorption Thick, porous layers absorb both high and low frequency sound
	E3	Sound propagations indoors - Absorption Cover layers with large perforations may be used without reducing absorption
	E4	Sound propagations indoors - Absorption Panels on studs absorb low frequencies
	E5	Sound propagations indoors - Absorption Sound barriers may be combined with sound absorptive ceilings
	F1	Sound propagation in ducts - Reactive mufflers All duct changes reduce sound transmission
	F2	Sound propagations in ducts - Reactive mufflers Expansion chambers are useful for reducing low-frequency noise
	F3	Sound propagations in ducts - Dissipative mufflers Dissipative mufflers are effective over a broad range of frequencies
	F4	Sound propagation in ducts - Reactive mufflers Reactive mufflers are effective in narrow frequency ranges
	F5	Sound propagation in ducts - Reactive mufflers Pure tomes can be eliminated by canceling sound
	F6	Sound propagation in ducts - Dissipative mufflers Unused spaces can be absorption chambers
	G1	Sound from vibrating machines - Machine mounting Machines which vibrate should be mounted on heavy, rigid bases
	G2	Sound from vibrating machines - Machine mounting Machines can be vibrations isolated with flexible elements
	G3	Sound from vibrating machines - Machine mounting Improperly selected isolators can increase vibrations
	G4	Sound from vibrating machines - Machine mounting Heavy machines producing low frequency vibrations require a rigid floor
	G5	Sound from vibrating machines - Machine mounting A separate foundation provides the best solidborne sound barrier
	G6	Sound from vibrating machines - Machine mounting Sound through connections must be blocked
	H1	Sound reduction of walls - TL The TL of a single wall is estimated from its surface weight
	H2	Sound reduction of walls - TL A single wall provides poor sound insulation around a certain frequency
	H3	Sound reduction of walls - TL Rigidity and weight are both important in thick walls
	H4	Sound reduction of walls - TL Light double walls provide good isolation
	H5	Sound reduction of walls - TL Double walls should have few connections

You will need to install the free Adobe Acrobat Reader viewer software to see the documents that are in Portable Document Format (PDF file).