Frequently Asked Questions

A decibel meter, also called a sound level meter or noise meter, measures the intensity of sound in an environment and reports it in decibels (dB). An online decibel meter does the same job in your browser using your device’s microphone — no hardware or app required.

When you press Start Measuring, the browser requests microphone access, then captures the audio and analyzes it in real time using the Web Audio API. The signal amplitude is converted into a decibel value and displayed live, together with minimum, average, maximum, peak, and Leq statistics. All processing happens locally on your device.

Yes. Every smartphone has a microphone, and this online decibel meter uses it to estimate the sound level around you. Results are useful for everyday checks and comparisons, but readings vary between devices by several dB and are not certified — calibrate against a trusted reference and use averages over 30–60 s for the most consistent results. See the phone decibel meter guide and methodology for details. Not suitable for legal, medical, occupational, or regulatory decisions.

Yes. The decibel meter is completely free: no downloads, sign-ups, subscriptions, or hidden features. It runs in your browser and works on phones, tablets, and computers.

No. The meter runs entirely in your browser, so there is nothing to install. Just open the page and allow microphone access when your browser asks for permission.

Yes. The microphone is the sensor — the meter captures sound through it and converts it to a dB reading in real time. Browsers always ask for permission first as a privacy safeguard. In this tool, the audio is processed locally on your device and is never uploaded or recorded.

An online decibel meter can give useful estimates for education and before/after comparisons when used carefully and calibrated against a trusted reference, but absolute accuracy is device-dependent and without calibration the error is unknown — different devices routinely disagree by 5–10 dB on the same sound. Consumer microphones are not calibrated instruments, so readings are for reference only, not certified measurements, and are not suitable for legal, medical, occupational, or regulatory decisions. The accuracy guide and validation protocol explain what affects readings and how to check your device.

A quiet room is typically around 30–40 dB, normal conversation measures roughly 60 dB, and busy street traffic sits in the 70–80 dB range. Typical everyday environments usually stay below 85 dB.

30 dB is very quiet — a soft whisper, a quiet library, or a bedroom at night. It is roughly the level of a refrigerator hum in a silent room and is safe for unlimited exposure.

60 dB is normal conversation at arm’s length, background music, or a running dishwasher. It is the everyday level of a typical home during the day and is safe for any duration.

70 dB is a busy street, a vacuum cleaner, or a loud conversation. Levels below 70 dB are generally considered safe regardless of duration; this is where "noticeably loud" begins.

80 dB is heavy traffic, a noisy restaurant, or an alarm clock. It is loud enough to make conversation effortful, but brief exposure is not a concern for most people.

85 dB is the level where prolonged exposure starts to matter: NIOSH recommends no more than about eight hours at 85 dBA. A noisy lawnmower or blender sits near here, and the safe duration halves with every 3 dB increase.

100 dB is a motorcycle, chainsaw, jackhammer, or headphones at maximum volume. The recommended exposure is roughly 15 minutes. It is common at live events and a frequent cause of ringing ears afterwards.

dB is the raw decibel reading of sound pressure level. dBA applies A-weighting, a frequency filter that mirrors the sensitivity of human hearing, so dBA values reflect how loud a sound actually sounds to people. dBA is the standard measure for noise exposure.

A-weighting is a frequency filter that mimics the human ear’s sensitivity: it attenuates very low and very high frequencies and passes the speech range unchanged. A-weighted readings (dBA) approximate perceived loudness and are the standard for environmental and occupational noise measurement.

C-weighting (dBC) is a much flatter curve that preserves low-frequency content, matching perception for loud, bass-heavy sound such as concerts, engines, and machinery. Z-weighting (dBZ) is a flat response with no frequency correction at all, used for raw acoustic measurements. The dB vs dBA guide compares all three.

Leq (equivalent continuous sound level) is the average sound energy over the whole measurement session. Unlike a simple average, it correctly accounts for energy, which makes it the metric professionals use to assess noise exposure.

RMS (root mean square) is the effective continuous level of a signal — it averages the waveform energy over a short window. It tracks perceived loudness better than instantaneous peaks and is the basis for the current dB reading on most sound level meters.

Yes. The meter measures whatever sound is present, so background or ambient noise is exactly what it captures. For a background noise reading, measure during a quiet moment, keep the device still, and use the minimum or average reading rather than single instants.

Place the device where people actually sit or stand, keep the microphone unobstructed, and measure for at least a minute while no one talks. Use the average or Leq reading and compare it with the common sounds chart. The how-to-measure guide walks through the full workflow.

Measure at the wall or floor where the noise enters, at ear height, for at least 10–15 minutes to capture the pattern. Note the maximum for short events like bass hits and the Leq for overall levels. Keep the microphone clear of the wall to avoid contact vibration, and remember that phone readings are estimates — not evidence.

Place the device at a student’s desk height in the center of the room, away from projectors and air vents, and measure across a full lesson period. The average and Leq tell you the typical level students experience; spikes above 80 dB show disruptive events.

Measure at ear height in the actual work position for the full shift or task period. Use Leq to estimate exposure and check it against limits (for example, 85 dBA over 8 hours). For formal compliance assessments you must use a certified sound level meter — see the noise exposure guide.

Yes. Place the device about one meter from the speaker, pointing at it, and measure during music playback. The average gives the typical level; the peak shows the loudest transients. Keep in mind that consumer microphones under-report deep bass, so subwoofer-heavy content reads lower than it sounds.

Play a known reference sound, such as a 94 dB calibration tone from a trusted source, note what the meter reads, then enter both values in the Calibrate dialog — the offset is calculated automatically. Calibration improves consistency but cannot make a consumer microphone a laboratory instrument. See the calibration guide for the full method.

Phone microphones have different sensitivities and frequency responses, and devices apply different amounts of automatic gain control, noise suppression, and echo cancellation. Two phones measuring the same sound commonly differ by 5–10 dB. Calibration against a known reference removes most of the difference.

Browsers require explicit permission before any website can access your microphone — it is a privacy safeguard built into every modern browser. The meter needs that access to hear and measure the sound around you, and it only works while you allow it.

No. Audio is processed locally in your browser using the Web Audio API and is never recorded, stored, uploaded, or listened to. No network request is involved in measurement, and you can verify this by measuring with your device offline.

No. For everyday awareness, comparisons, and education, an online decibel meter is genuinely useful. For regulatory compliance, legal evidence, workplace assessments, or any measurement that will be challenged, you need a certified sound level meter meeting standards such as IEC 61672 and calibrated by a laboratory.

No. Phone and browser measurements are estimates, not certified measurements, and are not accepted for legal or regulatory compliance purposes. Use a calibrated instrument that meets the applicable standard (for example, IEC 61672) and have measurements conducted by qualified professionals.

The minimum shows the quietest sound captured during the session, the maximum shows the loudest peak, and the average reflects the typical level over time. Leq is the energy-equivalent level for the whole session and is the metric professionals use to assess noise exposure.

Sustained exposure at or above 85 dB can damage hearing over time. Levels above 90 dB are increasingly risky, and sounds above 120 dB can cause immediate damage. Protect your ears at concerts, workshops, and other loud places, and use the noise exposure guide to understand safe durations.

70 dB is the level of a busy street, a vacuum cleaner, or a loud TV. It is noticeably louder than normal conversation (around 60 dB), but sounds below 70 dB are generally considered safe regardless of how long you hear them. Use the decibel meter to see whether your environment sits comfortably below this threshold.

To reduce noise at home: identify the loudest sources using the decibel meter and address them first; add soft furnishings (rugs, curtains, upholstered furniture) to absorb reflections; seal gaps around doors and windows; use white noise or a fan to mask steady background noise; and, for serious neighbor noise, consider acoustic panels or a professional acoustic assessment.

A frequency analyzer measures how sound energy is distributed across different frequencies. Instead of a single dB value, it shows which pitches are loud — for example, bass around 60 Hz versus speech around 2 kHz. This decibel meter includes a real-time frequency analyzer and audio spectrum analyzer in the Visualization panel: switch to the Spectrum tab while measuring to see your sound broken into frequency bands.

An audio spectrum analyzer displays the full sound spectrum visually, usually as a bar graph where low frequencies are on the left and high frequencies on the right. It is the same idea as a sound frequency analyzer — it helps you see whether noise is dominated by low rumble, mid-range speech, or high-frequency hiss. In this tool the spectrum analyzer updates live as you measure, alongside the waveform and level views.

Yes — this tool works as an online noise meter, sound meter, sound level meter and noise level meter. All of those terms describe the same function: measuring sound intensity in decibels (dB). Place your device where you want to measure, allow microphone access, and watch the live dB reading. For everyday checks the terms are interchangeable; professionals may use distinct hardware, but the measurement principle is identical.

Because decibels are logarithmic: two equal 70 dB sources combine to about 73 dB, not 140 dB. Each doubling of identical sources adds 3 dB, and a source 10 dB louder than everything else dominates the total almost entirely. This is why fixing the single loudest appliance matters far more than quieting several small ones.

Outdoors, away from walls, doubling the distance from a small source drops the level by about 6 dB — for example, 84 dB at 2 metres becomes roughly 78 dB at 4 metres and 72 dB at 8 metres. Indoors the drop is smaller (around 3–4 dB per doubling) because walls reflect sound back. Always note your measuring distance alongside the reading.

Use dBC when bass dominates: concerts, engines, generators, traffic rumble, and neighbour subwoofers. A-weighting discounts deep bass by up to 26 dB, so bass problems can read deceptively low in dBA — a room measuring 52 dBA but 71 dBC has a genuine low-frequency problem. Quote both numbers together whenever bass is the complaint.

Aim for 35 dBA or below at the pillow, measured as a 60-second Leq with windows closed. The WHO targets 45 dB outside at night, which typically means 30–35 dBA indoors. If your bedroom sits consistently above 45 dBA, check window seals and door gaps first, then consider soft furnishings or a quiet masking fan near 40 dB.

Record seven fields every time: date and time, exact mic position, device and browser, weighting setting (dBA or dBC), duration, the Leq/minimum/maximum numbers, and conditions such as windows open or closed. Log the same way for two weeks, export each session as CSV or JSON, and present it as screening data — honest phone estimates with dates persuade far better than adjectives or single screenshots.