NoiseFox: Sound & dB

NoiseFox is a precision decibel and sound level meter (SPL meter) designed for acoustics testing, environmental noise monitoring, workplace safety, and home audio calibration.

Equipped with real-time digital signal processing (DSP), IEC 61672 compliant A, C, and Z frequency weightings, and responsive Fast/Slow time integration, NoiseFox turns your smartphone into a capable acoustic analyzer.

PRECISION DECIBEL MEASUREMENT • Real-Time dB Meter: High-visibility arc gauge and digital readout showing current sound pressure level (SPL) in decibels. • Standard Frequency Weightings:

A-weighting (dBA): Matches human ear sensitivity curve. Best for environmental noise, workplace OSHA safety, and quiet spaces.
C-weighting (dBC): Emphasizes low-frequency sound. Ideal for checking subwoofer bass, machinery hum, HVAC, and music venues.
Z-weighting (dBZ): Flat unweighted acoustic response from 20 Hz to 20 kHz. • Fast & Slow Time Weighting:
Fast (125 ms): Captures rapid noise spikes, transients, and speech patterns.
Slow (1,000 ms): Smooths fluctuations to measure sustained ambient noise averages. • Comprehensive Sound Metrics: Monitor Min, Max, Peak, and Leq (equivalent continuous sound level) simultaneously. • 30-Second Real-Time Waveform: Instant visual sparkline showing acoustic level trends over time.
NOISE THRESHOLD ALERTS & HEALTH PROTECTION • Set custom decibel limits (e.g. 85 dBA recommended occupational threshold). • Receive instant visual warnings and haptic vibration when safe noise limits are exceeded. • Background noise monitoring with low-power persistent service and status bar readout.

13 REFERENCE NOISE LEVELS • Compare your surroundings against 13 real-world sound standards:

10 dB: Calm breathing
20 dB: Rustling autumn leaves
30 dB: Quiet whisper
40 dB: Library quiet
50 dB: Refrigerator hum
60 dB: Normal conversation
70 dB: Busy city street
80 dB: Vacuum cleaner & lawnmower
90 dB: Motorcycle engine
100 dB: Emergency siren & concert
110 dB: Chainsaw & power tools
120 dB: Jet aircraft takeoff (threshold of pain)
ACCURATE MULTI-STEP CALIBRATION • Calibrate to reference sound level meters or acoustic calibrators (94 dB / 114 dB). • Fine-tune microphone sensitivity with 0.1 dB precision slider. • Remembers separate calibration profiles for UNPROCESSED, VOICE_RECOGNITION, and DEFAULT microphone inputs.

HISTORY LOGGING & EXCEL CSV EXPORT • Save measurement sessions with 1-second interval time-series logs. • Interactive session viewer: Zoom in, pan across recordings, and inspect noise peaks. • Export data to standard CSV files (UTF-8 BOM formatted) compatible with Microsoft Excel, Google Sheets, and MATLAB.

100% PRIVATE & OFFLINE • Your privacy is absolute: NoiseFox processes raw audio samples entirely in local memory to calculate decibel levels. • Zero audio recordings are stored, saved to disk, or transmitted over the internet. • Completely offline functionality: No login or cloud account needed.

NoiseFox is free to use. An optional one-time Pro purchase removes all ads and unlocks unlimited saved session storage.