Acoustics Glossary
Welcome to AcSoft's Acoustics Glossary!
Whether you are new to acoustics or need a quick refresher, our bite sized videos break down complex acoustic terms into simple, easy to understand explanations.
We will cover all the essential terms you will encounter in environmental noise, building acoustics and beyond!
Have a question or want us to cover a specific acoustics term, contact us!
A-Z of Acoustic Terms
Accelerometers
Accelerometers are sensors used to measure vibration and movement, making them essential for vibration monitoring and analysis.
Acoustic Camera
Learn what an acoustic camera is, how it visualises sound, and why it is used to locate and analyse noise sources.
Class 1
Class 1 sound level meter's are high-precision instruments that are designed for professional acoustic measurements where legal compliance and accuracy is critical. Class 1 meters are defined by the international standard IEC 61672.
Dynamic Range
Dynamic range is the span between the quietest and loudest sounds a microphone or sound level meter can measure accurately.
Echo
An echo is a reflected sound that returns after the original sound, helping us understand how sound behaves in different environments.
Exposure Limit Value
Exposure Limit Values (ELVs) define the maximum level of noise or vibration a worker can legally be exposed to, helping protect health and ensure compliance.
FFT
FFT reveals the frequencies hidden within sound and vibration signals, making it one of the most powerful tools for analysing and diagnosing acoustic data.
Frequency Range
Frequency range is the span of frequencies a microphone, loudspeaker, or system can handle reliably. It’s usually defined between two cutoff points, where the output drops by 3 decibels compared to the flat response.
Geophone
Geophones detect vibrations that travel through the ground, converting them into electrical signals, making them crucial for vibration monitoring in construction, rail, and environmental monitoring.
LDEN
LDEN is an environmental noise metric used to represent average noise exposure over a 24-hour period, applying additional weighting to evening and night-time noise to reflect increased sensitivity to disturbance during these times.
LEP
LEP, or Personal Noise Exposure Level measures the total amount of noise someone is exposed to over their working day.
LEQ
LEQ, or Equivalent Continuous Sound Level, is one of the most important metrics in noise measurement and represents the average sound level over a set period.
LMAX
LMAX, or Maximum Sound Level, is the highest averaged sound pressure level recorded during a measurement period, based on a selected time weighting (like Fast or Slow).
LMIN
LMIN, or Minimum Sound Level, is the lowest sound pressure level recorded during a measurement period.
LPEAK
LPeak (Peak Sound Level) is the maximum instantaneous sound pressure level recorded during a measurement,
Noise Weighting
Noise weighting is all about how we measure sound in a way that reflects how humans actually hear it.
Octave Bands
Octave bands are frequency ranges that divide sound into manageable sections, making it easier to analyse data and identify noise problems.
Particle Velocity
Particle velocity describes the back-and-forth motion of air particles when a sound wave passes through.
Particulate Matter (PM)
Learn what particulate matter is, how it affects air quality, and why monitoring airborne particles is essential for environmental and health assessments.
Pascals vs Decibels
We explain how Pascals relate to decibels, why the conversion is needed, and how the dB scale makes it easier to compare sounds across environments.
Peak Particle Velocity
PPV, or Peak Particle Velocity, is one of the most commonly used measurements in vibration monitoring. It describes the maximum speed at which particles in the ground or a structure move during a vibration event.
Polarisation in Microphones
Polarisation is the electrical charge applied to a microphone’s diaphragm to make it sensitive to sound.
Reverberation Time
Reverberation Time — commonly referred to as RT60 — is the time it takes for sound to decay by 60 decibels after a sound source stops.
Sound Pressure Level
Sound Pressure Level (SPL) is a way of expressing sound in decibels, based on the pressure variations a sound wave creates in the air.
Time weighting
Time weighting determines how quickly a sound level meter responds to changing noise levels, making it essential for accurate noise measurement and analysis.
UKAS
UKAS is the UK's national accreditation body, ensuring testing and calibration organisations meet internationally recognised standards for accuracy, competence, and reliability.
VC Curves
VC Curves, or Vibration Criterion Curves, are used to define acceptable vibration levels for sensitive buildings, equipment, and spaces.
WAV
WAV is a high-quality audio format used to record, store and analyse sound for acoustic measurements and noise monitoring.
Knowledge Hub
National Civils Show 2026
November 2, 2026
We’re excited to announce that AcSoft and Svantek UK will be attending the National Civils Show 2026, taking place on 25th and 26th November. You’ll find us at stand EIA8, where we’ll be showcasing a selection of our air quality, noise and vibration monitoring solutions designed for civil engineering, construction…
SV 307A Black Edition: Your Questions Answered
October 22, 2026
We’re excited to release a new look for the UK’s favoruite noise monitor. The SV 307A is now available in black! It is the same Class 1 noise monitoring station as the white SV 307A, just repackaged in a subtle a black case. The colour is the only change. The…
Applications of the CRY8025 Acoustic Camera
September 9, 2026
Acoustic imaging is changing the way engineers and maintenance teams find and investigate problems. By turning sound into a visual image, an acoustic camera can quickly pinpoint where a sound is coming from – even when the source is difficult to locate by ear alone. The CRY8025 SonoCam Pocket Pro…
New Svantek Product: Introducing the SV 810 Air Overpressure Meter
September 2, 2026
When it comes to blast monitoring, accurate measurement of air overpressure is just as important as monitoring ground vibration. Blast events can generate significant pressure waves, particularly at low frequencies. That’s where the new SV 810 Air-Overpressure Meter from Svantek comes in. Designed specifically for blast monitoring applications, the SV…