science

Noise measurement

Noise measurement is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Noise measurement rather than just read about it. In short: In acoustics, noise measurement can be for the purpose of measuring environmental noise or measuring noise in the workplace. Applications include monitoring of construction sites, aircraft noise, road traffic noise, entertainment venues and neighborhood noise.

Key takeaways

Noise measurement belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Noise measurement to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Noise measurement from memory before moving on to harder problems.

Reference excerpt

In acoustics, noise measurement can be for the purpose of measuring environmental noise or measuring noise in the workplace. Applications include monitoring of construction sites, aircraft noise, road traffic noise, entertainment venues and neighborhood noise. One of the definitions of noise covers all "unwanted sounds". When sound levels reach a high enough intensity, the sound, whether it is wanted or unwanted, may be damaging to hearing. Environmental noise monitoring is the measurement of noise in an outdoor environment caused by transport (e.g. motor vehicles, aircraft, and trains), industry (e.g. machines) and recreational activities (e.g. music). The laws and limits governing environmental noise monitoring differ from country to country. At the very least, noise may be annoying or displeasing or may disrupt the activity or balance of human or animal life, increasing levels of aggression, hypertension and stress. In the extreme, excessive levels or periods of noise can have long-term negative health effects such as hearing loss, tinnitus, sleep disturbances, a rise in blood pressure, an increase in stress and vasoconstriction, and an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfering with reproduction and navigation, and contributing to permanent tinnitus and hearing loss. Various interventions are available to combat environmental noise. Roadway noise can be reduced by the use of noise barriers, limitation of vehicle speeds, alteration of roadway surface texture, limitation of heavy vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration, and tire design. Aircraft noise can be reduced by using quieter jet engines, altering flight paths and considering the time of day to benefit residents near airports. Industrial noise is addressed by redesign of industrial equipment, shock mounted assemblies and physical barriers in the workplace. Noise may be measured using a sound level meter at the source of the noise. Alternatively, an organization or company may measure a person's exposure to environmental noise in a workplace via a noise dosimeter. The measurements taken using either of these methods will be evaluated according to the standards below.

Audio Systems and Broadcasting Noise measurement can also be part of a test procedure using white noise, or some other specialized form of test signal. In audio systems and broadcasting, specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the inconsistent spectral distribution and temporal properties of the noise that they generate. In particular, the ITU-R 468 noise weighting was devised specifically for this purpose and is widely used for professional audio and broadcast measurements.

Standards There are a number of standards for noise measurement, each with a different goal or focus, including:

Standard:ITU-R BS 468 widely used in Broadcasting and professional Audio. Standard:IEC A-weighting is widely used in Environmental Noise measurement. Standard:CCIR recommendation 468-4 is now maintained as ITU-R BS 468 Standard:CCITT 0.41 refers to 'Psophometric weighting' used on telephone circuits. Standard:CCITT P53 is now continued as CCITT0.41 Standard:BS 6402:1983 specifies Personal sound exposure meters. Standard:BS 3539:1968 specifies Sound level meters for motor vehicle noise. Standard:BSEN 60651 supersedes BS 5969:1981 Sound level meters

See also Sound power level LWA Audio system measurements Rumble measurement Noise (environmental) Noise pollution Noise music Noise dosimeter Equal-loudness contour A-weighting C-weighting Weighting filter

References

External links Noise-Planet: app to make an open source noise map of environmental noise Koopen: Indoor Noise Measurement Dataset

Worked examples

Example 1 — a first encounter with Noise measurement

Start with the simplest possible case. Write down what Noise measurement claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Noise measurement before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Noise measurement ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Noise measurement

In research: Noise measurement appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Noise measurement in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Noise measurement is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acoustics, Noise, Noise pollution, so understanding it makes those chapters shorter.
In everyday life: Look for Noise measurement outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Noise measurement” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Noise measurement in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Noise measurement means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Noise measurement out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Noise measurement in simple terms?

Why does Noise measurement matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Noise measurement?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Noise measurement.