Decibel Meter: Sound Level

🔊 DecibelMaster Pro — Precision Sound Level Meter (SLM), Occupational Noise Dosimeter & Real-Time 9-Band FFT Octave Frequency Spectrum Analyzer! Engineered to meet rigorous acoustic measurement standards (IEC 61672-1 Type 2 compliance), DecibelMaster Pro transforms your Android smartphone into a professional, lab-grade sound pressure level (SPL) meter. Whether assessing workplace noise safety (OSHA / NIOSH compliance), tuning studio acoustics, investigating neighborhood noise, or monitoring hearing health, DecibelMaster Pro delivers unparalleled measurement precision, beautiful visual telemetry, and 100% on-device privacy. 🌟 CORE FEATURES & CAPABILITIES: 1. 🎙️ Laboratory-Grade Sound Level Meter (SPL) • Real-time digital sound pressure measurement with ultra-responsive analog dial and high-visibility digital readout. • Frequency Weighting Filters: - A-Weighting (dBA): Replicates human ear response for everyday environmental & occupational noise. - C-Weighting (dBC): Captures low-frequency bass, engine rumble, subwoofers, and machinery noise. - Z-Weighting (dBZ): Flat acoustic response across the audible spectrum. • Time Weighting Dynamics: Fast (125ms) for rapid transients and Slow (1000ms) for stable time-averaged levels. • Complete statistical matrix: Instantaneous dB, MIN, Time-Average (AVG / Leq), MAX, and Absolute PEAK. 2. 📊 Real-Time 9-Band 1/1 Octave FFT Spectrum Analyzer • Radix-2 Cooley-Tukey Fast Fourier Transform (FFT) algorithm with Hann windowing. • Visualizes acoustic energy across 9 standard IEC octave frequency bands: 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, 8 kHz, and 16 kHz. • 3 interactive visualizer modes: Real-Time Oscilloscope Waveform, Chrono-Trend History Line, and 9-Band Animated Equalizer. 3. ⏳ Occupational Noise Dosimeter & 8-Hour TWA • Dual Standards Support: - OSHA PEL: 90 dBA Criterion, 85 dBA Threshold, 5 dB Exchange Rate. - NIOSH REL: 85 dBA Criterion, 80 dBA Threshold, 3 dB Exchange Rate. • Computes Cumulative Shift Dose (%), Remaining Safe Permissible Hours, and 8-Hour Time-Weighted Average (8H TWA). • Extrapolates Projected 8-Hour Daily Dose in real-time. 4. 🛡️ Background Monitoring Foreground Service • Continuous acoustic monitoring with screen locked or app minimized. • Low-overhead persistent status bar notification displaying live decibel levels and hazardous noise warnings. • Instant notification alerts when sound levels exceed danger thresholds (e.g. 85 dBA). 5. 📁 Session Recording, History & CSV/JSON Export • Save full measurement runs with titles, location tags, and custom notes. • Review past sessions with interactive telemetry cards and historical trend graphs. • Export session data seamlessly to CSV and JSON for safety audits or noise complaints. 6. 🎯 Manual Acoustic Offset Calibration • Fine-tune microphone sensitivity (+/- 20.0 dB in 0.1 dB increments) against calibrated reference sound sources. 7. 🌓 3 Curated Themes & Multi-Language Engine • Dark Studio, OLED Stealth Pitch Black, and Acoustica Clean Light. • Fully localized across global languages with instant dynamic switching. 🔒 100% PRIVATE — ZERO AUDIO RECORDED: DecibelMaster Pro computes sound pressure purely in ephemeral RAM. No audio or voice recordings are ever recorded, saved to storage, or transmitted over any network. ⚖️ LEGAL DISCLAIMER: Intended for personal awareness, education, and reference monitoring. Built-in smartphone microphones cannot substitute certified Class 1 / Class 2 laboratory instruments.