Decibel Meter
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Decibel MeterSTANDBY
ANALOG SIGNAL GENERATOR · CRT PHOSPHOR SCOPE · 20Hz - 22,000Hz
Sound Pressure Level (SPL) Meter
Sensitivity Trim
A-Weighted Sound Pressure Level (dBA)
30507085100120A-Weighted Sound Pressure Level (dBA)
Silent studio / whisper level
Faint whispers and rustling leaves (below 40 dB)
Instant Ambient SPL
35.0dB
Fast Damped Ballistics · RMS Energy
Peak42.5
Min32.1
Max48.0
Leq Avg38.2

Online Decibel Meter - A-Weighted Sound Level

Acoustic Reference Guide

What Is A-Weighted Sound Level and What dB Level Is Safe?

A-weighted decibels match how human hearing actually perceives loudness. This guide explains A-weighting and lists the safe daily exposure limits recommended by OSHA and the WHO.

A Sound Level Meter quantifies physical sound wave pressure. This instrument implements standardized A-weighting filtering to mimic the 40-phon Fletcher-Munson equal-loudness curve, matching human hearing sensitivity for acoustic safety analysis.

A-Weighting (dBA) Equal Loudness Filter

Attenuates frequencies below 500 Hz where human ears are naturally less sensitive, accurately reflecting occupational loudness and hearing damage potential.

Fast Ballistic Analog Meter

Implements a 125ms Fast time constant mimicking industrial analog sound meters.

Technical SpecificationsCALIBRATED AUDIO ENGINE
Dynamic Range30 dBA to 120 dBA
Weighting StandardA-Weighting (IEC 61672 Class Compliant Approximation)
Frequently Asked Questions

Continuous exposure above 85 dBA can cause irreversible sensorineural hearing loss. OSHA limits daily 85 dBA exposure to 8 hours; every 3 dB increase halves the safe time limit.

Key facts and specificationsQUOTABLE FIGURES
What is the measurement range?
30 dBA to 120 dBA.
What does A-weighting do?
It applies the IEC 61672 A-weighting curve, which attenuates low and very high frequencies to match how human hearing perceives loudness.
How fast does the meter respond?
Fast ballistic damping with a 125 millisecond time constant, matching a classic analog sound level meter.
Which readings are displayed?
Current level, peak hold, maximum, minimum and the equivalent continuous sound level Leq.
How long is it safe to be exposed to 85 dB?
OSHA limits daily exposure to 85 dBA to 8 hours. Every additional 3 dB halves the safe time, so 88 dBA allows 4 hours and 91 dBA only 2 hours.
Is this a certified sound level meter?
No. Accuracy depends on your device microphone sensitivity and automatic gain control. Use the calibration trim to match a known reference, but this is not a traceable IEC 61672 Class 1 instrument.
ISO 16 / ISO 226 equal-loudness standardsIEC 61672-1 sound level meter specification
GEO SEMANTIC GRAPH // ENTITY INDEXED
Zero-Latency Tactile Feedback

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Vintage Tube & Atmospheric Noise

Synthesizes authentic hyperbolic tube warmth with even/odd harmonics, alongside tunable radio static hiss and random contact pops.

Studio Master WAV Export

Render sustained tones, binaural beats, and logarithmic sweeps to uncompressed 16-bit 44.1 kHz WAV files for testing, acoustic tuning, or sharing.