Sound Pressure Level Meter App

Sonoscope is a professional sound pressure level meter app that turns your phone into a real decibel meter — not a toy dB reader. It implements the same weighting curves, time detectors and metrics defined by IEC 61672 and IEC 61260, so the numbers you see mean what they mean in acoustics.

MEASURE SOUND PRESSURE LEVEL IN REAL TIME • Live SPL readout in dB with a large, glanceable meter • A, C and Z frequency weighting per IEC 61672-1 • Fast (125 ms), Slow (1 s) and Impulse (35 ms) time detectors • LCpeak measured the way the standard defines it • Colour-coded levels so you instantly see when noise gets risky

FULL SET OF ACOUSTIC METRICS This sound level meter app records every metric an acoustician actually reports: • LAeq — equivalent continuous sound pressure level • Lmax, Lmin and peak level • SEL (sound exposure level) • L10, L50, L90 statistical levels for intrusive noise vs. background • Elapsed time and full session history

NOISE DOSIMETER & HEARING PROTECTION Track your daily noise dose against the standard your workplace uses: • NIOSH (85 dB / 3 dB exchange) • OSHA (90 dB / 5 dB exchange) • EU Directive 2003/10/EC See your dose percentage, projected 8-hour exposure and remaining safe time — a real noise dosimeter, not a guess.

REAL-TIME SPECTRUM ANALYZER • 4096-point FFT with Hann window and Parseval-correct scaling • Octave and 1/3-octave band analysis per IEC 61260 • Live spectrogram to see how noise changes over time • Identify the exact frequency causing a hum, rattle or whine

ROOM ACOUSTICS — RT60 REVERB Measure reverberation time and evaluate how a room sounds. Useful for studios, offices, classrooms, home theatres and podcast spaces.

NOISE MAP Log measurements with location to build a noise map of a site, a route or a neighbourhood — ideal for documenting noise complaints.

CALIBRATION FOR ACCURACY Every phone microphone is different. Calibrate with a reference sound source or an offset, with a built-in device calibration table, so your decibel meter readings stay accurate and repeatable.

PROFESSIONAL REPORTS & EXPORT • Export sessions to CSV for spreadsheets and analysis • Generate polished PDF measurement reports • Tamper-evident integrity chain on stored sessions • Perfect evidence for noise complaints, OSHA documentation, landlord disputes, HR reports and site surveys

WHO USES THIS SOUND LEVEL METER APP • Workers checking factory, workshop and construction site noise • Safety officers and industrial hygienists running exposure surveys • Musicians, DJs and live-sound engineers protecting their hearing • Studio owners and AV installers tuning rooms • Teachers measuring classroom noise • Parents checking nursery, toy and concert levels • Anyone documenting neighbour, traffic, HVAC or construction noise

PRIVATE BY CONSTRUCTION Audio is analysed in memory and never written to disk — only the derived levels are stored. No account, no ads tracking you, no recordings uploaded. Sonoscope makes a single anonymous install ping on first open, and nothing else ever leaves your device.

WORKS IN THE BACKGROUND Start a measurement session and keep it running while you use other apps or your screen is off.

IMPORTANT — NOT A CERTIFIED INSTRUMENT Sonoscope implements the standards' maths faithfully, but a phone is not a Class 1 or Class 2 sound level meter. Microphone frequency response and directivity are not controlled, and no phone can be certified. Use these numbers to understand, compare and document noise — not to certify legal compliance.

Download Sonoscope and find out exactly how loud your world really is.