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.