Skip to content
AkerminMeasure. Monitor. Improve. Compare Products
Guide

How to Choose a Sound Level Meter

The gap between a sound meter that supports a decision and one that does not is the IEC 61672 class and a calibrator. Beyond that, the choice is about integration (Leq), logging and the range you need.

By the Akermin Editorial Team · 3 min read

As an Amazon Associate, Akermin earns from qualifying purchases. Product links on this page are affiliate links.

Choose a sound level meter by the use. For anything compared with a limit, a specification or another person’s measurement, buy a meter that states IEC 61672 Class 2 (or Class 1 for environmental and legal work) and an acoustic calibrator to go with it. Require A and C weighting, fast and slow response, and Leq integration for exposure and planning measurements. Add data logging and PC output for reports, a windscreen for outdoor use and a tripod mount. For a rough idea of loudness, an unclassified consumer meter is fine and a phone app is nearly as good.

Step 1: Class

Class Tolerance at 1 kHz Use Typical examples
Class 1 ±1.1 dB, 16 Hz to 16 kHz Environmental noise, legal evidence, research, acoustic consultancy Brüel & Kjær, NTi, Svantek, Cirrus Class 1
Class 2 ±1.4 dB, 20 Hz to 8 kHz Workplace noise surveys, equipment checks, general complaints Extech SL510, 407732-KIT, Reed, Cirrus Class 2
Unclassified Not tested to the standard Rough loudness checks, home theater setup, hobby TopTes TS-501B, many consumer meters

See what a sound level meter is.

Step 2: Functions

  • Weighting: A for almost everything; C for peaks and low-frequency noise; Z for analysis. See what dBA means.
  • Time response: fast (125 ms) and slow (1 s), selectable.
  • Integration: Leq over a set period; Lmax and Lmin; percentiles (L10, L90) for environmental work; peak (LCpeak) for impulsive noise.
  • Range: 30 to 130 dB covers most uses; a single wide range avoids range switching errors.
  • Resolution: 0.1 dB.
  • Frequency analysis: octave or third-octave bands on higher-end meters, for diagnosing sources.

Step 3: Calibration

An acoustic calibrator produces a reference tone (94 dB or 114 dB at 1 kHz) that fits over the microphone. Check before and after each session; a change of more than 0.5 dB invalidates the session. Meters that accept a calibrator have a standard 1/2-inch or 1/4-inch microphone. Some Class 2 meters are sold as a kit with the calibrator (Extech 407732-KIT). Periodic laboratory calibration of both meter and calibrator is required by measurement standards for professional use.

Step 4: Logging and output

Internal logging of Leq and levels over time, and USB or Bluetooth output to a computer or app, turn a measurement into a report. For workplace surveys and long environmental measurements this is essential; for a one-off check, the display suffices.

Step 5: Accessories

  • Windscreen (foam ball) for any outdoor or fan-adjacent measurement.
  • Tripod with the meter’s 1/4-inch thread, to keep the operator’s body away from the microphone.
  • Extension cable for the microphone on higher-end units.
  • A case; microphones are fragile.

Recommendations by use

Use Choose
Checking a noisy appliance or neighbor for your own information Unclassified meter or app
Home theater and studio level setting Unclassified meter with C weighting and slow response
Workplace noise survey, equipment specification check Class 2 with Leq and a calibrator
Noise complaint to a council or landlord Class 2 minimum with logging; Class 1 if it may go further
Environmental assessment, planning, legal Class 1 with logging, percentiles and octave bands; professional calibration

Sound meters are covered in the environmental monitoring category alongside multifunction meters; see how to choose an environmental meter.

Extech SL510 Sound Level Meter, 35-130 dB, Class 2

Extech SL510 Sound Level Meter, 35-130 dB, Class 2

View on Amazon
Decibel Meter, TopTes TS-501B Sound Level Meter with 2.25” Backlit LCD Screen, Portable SPL Tester with A/C Weighted, Range 30-130dB, MAX/MIN, Data Hold, Use for Home, Noisy Neighbor, Factory - Orange

Decibel Meter, TopTes TS-501B Sound Level Meter with 2.25” Backlit

View on Amazon
Extech 407732-KIT Sound Level Meter Kit, 35-130dB, with Calibrator

Extech 407732-KIT Sound Level Meter Kit, 35-130dB, with Calibrator

View on Amazon

Products shown because their documented specifications fit this guide. Price and availability are on Amazon and can change.

Frequently Asked Questions

Do I need a Class 2 sound level meter?

For workplace noise assessments, equipment checks against a specification, and most complaints, yes. For a rough idea of how loud something is, an unclassified meter or even an app is enough.

What is Leq and do I need it?

Equivalent continuous level: the constant level with the same energy as the fluctuating sound over a period. Any measurement against an exposure limit or a planning condition needs it.

Do I need a calibrator?

For any measurement you will report or rely on, yes. A 94 dB or 114 dB acoustic calibrator confirms the meter before and after each session and is required by measurement standards.

Affiliate disclosure: Akermin earns a commission from qualifying Amazon purchases made through links on this page. Our editorial picks are based on documented specifications and owner feedback, not commissions.