Soundproof Cow :: Glossary




Absorption - The property of a material's composition to convert sound energy to heat energy. This will reduce the amount of sound reflected.

Absorption Coefficient - The fraction of sound energy absorbed into a surface, valued between 0.0 and 1.0.

Acoustic Panel - Fabric covered material placed on walls or ceiling to absorb sound.

Acoustics - The science of sound. Also acoustics describe physical characteristics of a space that affect sound quality (size, shape, amount of noise).

Acoustical - The properties of a material to absorb or reflect sound (adjective acoustically, (adverb).

Acoustical Analysis - Reviewing a space to determine how reverberation and reflections affect the sound quality of a room. This is also influenced on the building materials and how the space is structured. An analysis will also evaluate the amount of absorption acoustics needed to control noise.

Acoustical Consultant - An engineering professional with qualifications and experience to provide advice on acoustical requirements and noise control of a given situation.

Acoustical Environment - Acoustical characteristics of a space or room influenced by its acoustical performance, or lack there of.

Acoustical Material - A material used to influence a sound field. The materials can be used to absorb, block, or dampen sound energy.

Acoustical Panel - Specialized construction panel placed on a wall or ceiling to absorb sound.

Airborne Sound - Sound waves carried through the air to the receiver.

Ambient Noise - Applies to all noise in a space. In a room with no occupants, there can still be ambient noise such as autonomous HVAC or noises outside the space.

Anechoic Room - A room designed to suppress internal sound reflections. Used for acoustical measurements and testing.

A.N.S.I. - The American National Standards Institute

Architectural Acoustics - Noise control of a building space to facilitate good communication functions and its effect on occupancy. The structure's building materials have an effect on the building's distant hearing and acoustics.

Articulation Class (AC) - AC rates a ceiling's suitability for achieving normal speech privacy in open spaces by absorbing noise reflected at an angle off the ceiling into adjacent cubicles.

Articulation Index (AI) - A measure of speech intelligibility influenced by a room's acoustical environment including sound path obstructions and background noise. An AI is a rating between 0.0 and 1.0, higher number being better speech intelligibility.

Aspect Ratio - Aspect ratio describes the proportional relationship between an image’s height and width. This relationship does not change without some drastic changes (stretching or cropping) to the image. The easiest way to understand this is the following: to make a square image rectangular, you’d have to stretch the square, and to make a rectangular image square, you’d have to crop some pieces.

Attenuation - A reduction in sound energy, exponentially by a medium or a function of distance traveled.

Area Effect - Use of various acoustic materials spaced apart to achieve better absorbance than huddled together.

Assistive Listening Device (ALD) - A device that improves hearing for those who are hearing impaired and can be used in conjunction with a hearing aid for better communication. Some systems are personal frequency modulation, infrared, and induction loops, as well as a standard hearing aid device for one to one communication.

ASTM - American Society for Testing and Materials.

Audio Frequency - A periodic vibration of a sound wave that is audible to the human ear, measured between 20 and 20,000 Hz.

Audiogram - A graph representing an individual's hearing loss.

Audiometer - An instrument used to measure an individual's hearing ability.

A-Weighting - A frequency response adjustment of a sound-level that makes its reading conform, very roughly, to human response. Sound meter can ignore low frequency sound much like the ways our ears do.



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.



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 -



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.



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.



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.



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.



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



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.



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.



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.



Octave - Two to one ratio between frequencies.

Octave Band -

Octave Band Level -

Oscillation -

OSHA - The Occupational Safety & health Administration.



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



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.



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.



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.



Ultrasonic/Ultrasounds - Sounds higher than 20,000 hertz



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 -



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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