Glossary

B

Background Noise – The sum of all noise in a
situation and space, apart from the noise from the source of
interest.

Baffle – An acoustical absorber suspended from
the ceiling to reduce reverberation and absorb sound energy.

Band – Segment of the frequency spectrum.

Broadband Noise – A common industrial noise
typically described as a rumble, roar, or hiss.

Boom – Low frequency signals characterized by
deep resonant sounds.

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C

Calibrator (Acoustical) –

Carpet Classifications – According to the
Carpet Cushion Council (CCC) carpets are rated in three
categories: Class I – Moderate traffic (private offices,
administration), Class II – Heavy traffic (bank lobbies, hotel
hallways), Class III – Extra Heavy traffic (school hallways,
airports, restaurant dining areas)

Cochlea – The portion of the inner ear that
changes mechanical vibrations of cochlear fluid into electrical
signals. It is the frequency analyzing portion of the hearing
system.

Cutoff Frequencies – A frequency where a
pass-band and a stop-band meet.

Cycle – Complete oscillation of pressure above
and below the atmospheric static pressure

Cycles per second – Number of oscillations per
second.

Cylindrical Wave –

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D

Damping / Decoupling – When material is
applied to a solid structure, it will dissolve vibratory energy
similar to absorption of sound in the air.

dB vs. dB(A) – Decibels (dB) are a measurement
of sound intensity over the standard threshold of hearing. dBA
is sound intensity with an “A” contour filter. The filter
adjusts the measurement to account for the way in which the ear
responds to different frequencies of sound.

Decibel – unit of measure for sound pressure
levels, abbreviated dB.

Diffraction – The bending of sound waves when
they run into obstacles in their path.

Diffusion – The scattering of sound waves due
to reverberation. It tends to give the effect of coming from
different directions.

Directivity Index –

Dissipative Silencer – A device interested
into the air duct or opening to reduce noise transmitted through
the area. Noise reduction is accomplished through the use of
internal sound absorbing materials.

Doppler Effect (Doppler Shift) – The change in
frequency of a sound in relation to its location and of its
listener. The sound would have a higher perceived frequency if
the noise is moving closer and a lower perceived frequency when
the noise is moving away.

Dosimeter – A device used to measure an
individual’s exposure to a hazardous environment over a long
period of time such as loud noise or radiation.

DPI – To give you the best panel possible, we
need a very high quality image. We require a minimum of 300 dots
per inch – and the higher the resolution, the better.

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E

Echo – Reflected sound that continues to
resonate the original sound, but can be differentiated by a
delay.

Equal-Loudness Contour – Graph representation
of sound pressure on the frequency spectrum, where the listener
hears a constant and equal sound when presented with steady
tones.

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F

Fire Classification Ratings – Class A trade fires
are characterized as regular combustibles such
as wood, cloth and paper. Class B is flammable liquids such as
gasoline, oil & paint. Class C is electrical equipment such
as wiring, fuse boxes & appliances. Class D is combustible
metals, including magnesium, aluminum and lithium.

File Type – For all images, photos shot in the
raw camera settings will be the easiest for us to work with.
Photos can in in .pdf, .jpg, .tiff, .gif, .eps, .psb, .ai, or
.psd. Logos work best in .ai, .esp, or any type of vector file.

Filter – A device that separates signal
components by frequency. This would allow some signals to pass
through and others to be attenuated.

Flame Spread – Classification given to a
material comparing flame swelling to that of concrete or red
oak.

Flanking – Nose that reaches a listener by
paths around or over the acoustical barrier.

Flutter Echo – Ringing reverberation that
remains after the initial sound as stopped.

Free Field – Noise transmission outdoors where
there are no obstacles or boundaries.

Frequency – The measure of the rapidity of
alternations of a periodic signal, expressed in cycles per
second or HZ.

Frequency Analysis – An analysis of sound to
determine the character of the sound by decided the amount of
sounds at various frequencies that make up the overall sound
spectrum.

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H

Hair Cells – The sensory receptors in the
cochlea of the auditory system that transforms mechanical sound
energy into nerve impulses.

Harmonics – Integral multiples of the
fundamental frequency. The first harmonic is the fundamental,
and the second is twice the frequency of the first and so on.

Hearing – Human response to sound.

Hearing Loss/Impairment – The loss of
sensitivity of the auditory system, measured in dB below a
standard level. Some hearing loss can be attributed to exposure
to high-level sound.

Hertz (Hz) – Unit of frequency, abbreviated
Hz. The same as cycles per second.

Human Hearing Range – The range of the human
ear is anything between 20 and 20,000 hertz.

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I

Image Size – Our panels come in a variety of
sizes and you may choose a thickness of either 1” or 2”.
Depending on the wrap style you have chosen, the thickness will
determine how much of the image will wrap around the side or how
much of a border you need to add.

Impact Insulation Class (IIC) – A
single-figure rating given to a floor or ceiling assembly based
on its ability to block impact sound.

Impact Sound – The sound produced by the
collision of two solid objects. Typical sources are footsteps,
dropped objects, etc on an interior surface (wall, floor, and
ceiling) of a building.

Impulse Noise – A sharp sound pressure peak
occurring quickly, such as a gunshot or factory punch press).

Infrasound – Sound at a frequency level too
low to hear by humans.

Insertion Loss – The reduction of sound power
level attained by inserting a silencer or muffler in an acoustic
transmission system.

Intensity – Acoustic intensity is sound energy
flux per unit area. The average rate of sound energy transmitted
through a unity area normal to the direction of sound
transmission.

Inverse Square Law – Used to measure the sound
intensity at a given distance from the source. Sound falls off
with increasing distance (6 dB with each doubling distance).

I.S.0. – The International Organization for
Standardization

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L

LEED Certification – Leadership in Energy
& Environmental Design (LEED) certification provides
independent, third-party verification that a building project
meets the highest green building and performance measures.

Level – A sound pressure level in dB is
calculated in a standard reference level of 20 µPa. (See
this chart)

Live End/Dead End – An acoustical treatment
plan for rooms in which one end is highly absorbent and the
other is reflective and diffusive.

Logarithm –

Loudness – The subjective human judgment of
sound intensity and magnitude.

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M

Masking Noise – When only one of two sounds
can be heard because one of them is so strong and loud that it
makes the other inaudible or unintelligible.

Mass – Property important to sound
transmission loss through a material. The thicker the material,
the greater STL.

Medium – A substance that carries or
transports a sound wave.

Mounting – Standards established by ASTM to
represent typical installation for purpose of testing materials.

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N

Noise – Any undesired sound not occurring in
nature and interfering with communication or annoying the
receiver.

Noise Criteria (NC) – Characterized by
standard spectrum measurements which are used to evaluate
listening conditions at ear level.

Noise Isolation Class (NIC) – Number rating of
a space measured for its ability to reduce noise between two
areas.

Noise Reduction (NR) – The amount of noise
reduced in an area due to the introduction of soundproofing
materials or otherwise altering the sound field.

Noise Reduction Coefficient (NRC) – Absorptive
materials are tested in their performance to absorb the noise.
Labs quantify the amount of sound a particular surface material
absorbs and assigns to it a value referred to as the NRC. It
takes the average of the sound absorption coefficients in the
octave bands, centered at 250, 500, 1000, and 2000 Hz.

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O

Octave – Two to one ratio between frequencies.

Octave Band –

Octave Band Level –

Oscillation –

OSHA – The Occupational Safety & health
Administration.

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P

Peak Sound Pressure –

Period –

Permanent Threshold Shift (PTS) –

Phon – The unit of loudness level of a tone

Pink Noise – A noise signal whose spectrum
level decreases at a 3 dB per octave rate. This gives the noise
equal energy per octave

Pitch – The perceived frequency of a tone

Plenum – In buildings, these are enclosed
spaces that are not for human occupancy, but are often used for
heating, ventilating, and/or air-conditioning equipment and
airflow, and for other equipment such as cables, piping and
lighting.

Pure Tone – A tone with no harmonics and is
single in pitch and frequency

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R

Random Noise – A noise signal, commonly used
in measurements, which has constantly shifting amplitude, phase,
and frequency and a uniform spectral distribution of energy..

Reflection – 1) sound wave bouncing off a
surface. 2) The amount of sound wave energy that bounces back.
Hard non-porous surfaces reflect more sound than soft, porous
surfaces.

Refraction – The bending of a sound wave from
its original path when traveling through a medium with different
properties and velocities.

Resonance – A resonant system vibrates at
maximum amplitude when tuned to its natural frequency.

Resonator – A device that resounds or vibrates
in unison with a source of sound or vibration.

Reverberation – The tailing off of sound in an
enclosure because of multiple reflections off the walls or
boundaries.

Reverberation Chamber – A room with hard
boundaries used for testing sound absorption. The room is
designed so the reverberation intensity is the same in all
directions

Reverberation Time (RT) – The time after a
sound stops but continues to reflect off surfaces until it loses
sound energy due to absorption.

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S

Sabin – The unit of measure of sound
absorption, equivalent of one square foot of a perfectly
absorbent surface.

Septum – A thin layer of material sandwiched
between two layers of absorptive material, such as foil, lead,
steel, etc. Material prevents the sound wave from piercing
through the absorptive material.

Shielding – The attenuation of a sound,
achieved by placing barriers between a sound source and the
receiver.

Signal-to-noise ratio – The difference between
the nominal or maximum operating level and the noise floor in
dB.

Sone – The unit of measurement for subjective
loudness.

Sound – Sound could be

Sound Absorption – When a material, object or
air space that converts a sound’s energy into heat Sound waves
reflected by a surface cause a loss of energy and energy not
reflected becomes the material’s absorption coefficient.

Sound Absorption Coefficient (SAC) – The
remaining reflected energy when a material absorbs sound energy.
It is rated between 0 and 1. If a material absorbs 80% of the
sound, the SAC would be 0.20.

Sound Barrier – A material that, when placed
between a noise and its receiver, stops the transmission of the
sound.

Sound Level Meter – An instrument comprised of
a microphone, amplifier, output meter, and frequency weighting
networks, which is used to measure sound pressure level.

Sound Pressure – The instantaneous difference
between the pressure of a space and the new pressure of some
sound wave.

Sound Pressure Level (SPL or Lp) – A measure
of the air pressure change caused by a sound wave.

Soundproofing – Blocking sound transmission
from one space to another space.

Sound Transmission Class (STC) – A number
which rates partitions, walls, doors, windows and barrier
materials for their effectiveness at blocking sound from one
room to the next.

Sound Transmission Loss (STL) – The difference
in the noise level striking the barrier and what gets through is
the STL. Materials are tested and rated for their performance.
The higher the STL number stated in dB, the better the barrier.
Barriers perform better with the increasing frequency.

Spectrum – The description of a sound wave’s
components of frequency and amplitude.

Speech Interference Level (SIL) – A
calculation to measure the effect of background noise on speech
communication.

Spherical Divergence –

Spherical Wave –

Staggered Stud Wall – A studded wall designed
to have contact with drywall on only one side, effective at
reducing noise transmission. Instead of a typical stud wall
where the stud is in connected to both pieces of drywall, the
support is intermittent with a winding insulation throughout.

Structure Borne Noise – Sound traveling by
means of structure vibration is usually unnoticed but can become
audible and a problem.

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T

Temporary Threshold Shift (TTS) –

Threshold of Audibility –

Threshold of Pain –

Threshold Shift –

Timbre –

Time Weighted Average (TWA) – OSHA uses this
term in measuring a worker’s exposure to noise over an 8-hour
day.

Tonal Noise – Discrete frequency noise
characterized as annoying and repetitive. Some examples could be
fans, compressors, saws, motors and pumps.

Transducer – A device for changing electrical
signals to acoustical or vice versa, such as a microphone or
loudspeaker.

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U

Ultrasonic/Ultrasounds – Sounds higher than
20,000 hertz

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V

Vibration – The oscillation, reciprocation or
other periodic motion of a rigid or elastic body or medium
forced from a position or state of equilibrium.

Vibration Insulator – Support for a machine or
mechanical system to reduce the amount of vibration transmitted
to other objects or structures.

Viscoelastic –

Volatile Organic Compounds (VOC) – VOCs are
organic gases emitted from solid or liquids and can have
short-and long- term effects on health. The concentrations are
much worse indoors.

Volume –

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W

Wave – A disturbance propagated from point to
point in a medium or space without progress or advance by the
points themselves, as in the transmission of sound

Wavelength – The distance between two points
on any two successive waves. Low frequency has longer
wavelengths and higher frequency has shorter wavelengths.

White Noise – Random noise with a uniform
frequency spectrum over a wide range of frequencies.

Wrap Style – To attach your image to the
panels, we offer two options for display: Gallery Wrap and
Museum Wrap. Gallery Wrap stretched the canvas so that the image
continues over the sides of the panel. Museum Wrap keeps your
image entirely on the front of the panel, using a border on the
sides.

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