Decibel
Calibrated sound pressure level meter. High-precision DSP, 100% Free.
Test Decibel Engine in Browser
Simulate real-time RMS acoustic pressure sampling in volatile RAM with dBA weighting.
Decibel converts your smartphone into a calibrated acoustic measurement tool designed for audio engineers, environmental noise inspectors, studio acoustic technicians, and workplace safety compliance.
Unlike generic noise meter apps that upload microphone recordings or stream background telemetry, Decibel runs a low-latency C++ RMS DSP pipeline in volatile RAM. Microphone buffers are processed into mathematical decibel readings and immediately erased.
100% free with customizable dBA (human ear frequency curve), dBC (industrial bass response), Leq continuous equivalent sound pressure, and a deep OLED darkroom interface for live stage and studio use.
- Category
- UTILITY
- Platform
- ANDROID & IOS
- Binary Size
- 3.8 MB
- Min Target OS
- Android 8.0+ / iOS 15.0+
- Version
- 2.1.0
- Offline Ready
- 100% On-Device
- Telemetry Trackers
- 0 Trackers
- Advertisements
- Zero Ads
- Monetization
- 100% Free
Laboratory-grade acoustic signal processing
Precision Weighting Filters (dBA, dBC, Z)
Mathematically accurate digital filtering curves conforming to IEC 61672:2013 standards for industrial and studio acoustic monitoring.
Equivalent Continuous Level (Leq)
Computes true energy-averaged continuous noise levels over time, crucial for OSHA compliance and environmental noise audits.
Zero Audio Recording Architecture
Microphone input is processed strictly in mathematical buffers to compute root-mean-square (RMS) sound pressure and immediately purged from RAM.
Hardware Microphone Trim Offset
Fine-grained manual calibration tool with ±25 dB adjustment to calibrate against Class 1 or Class 2 reference calibrators.
OLED Darkroom High-Contrast Mode
True #000000 background display engineered to prevent glare in darkened recording studios, control rooms, and live theater stages.
100% Free & Ad-Free
Free forever with zero banner ads, zero popups, and zero subscription paywalls.
Decibel vs Legacy Alternatives
| Metric | Decibel (Outlayer Labs) | Standard App Store Apps |
|---|---|---|
| Price & Monetization | 100% Free (Zero Ads, Zero Upsells) | $3.99/week or flashing banner ads |
| Audio Recording / Audio Storage | Strictly Zero (Memory-only RMS) | Often saves audio clips for cloud AI |
| Frequency Weighting Curves | dBA, dBC, Z-weighting (IEC-standard) | Unweighted raw amplitude |
| Microphone Calibration | ±25.0 dB Precision Trim | Fixed, uncalibrated approximations |
| Offline Reliability | 100% Offline | Requires online connection |
Interface Previews & Telemetry
Live SPL Gauge
High refresh-rate analog-style needle and digital readout
Leq & Peak Capture
Clean statistical metrics without noisy graphs
Calibration Suite
Hardware-level microphone sensitivity trimming
100% Free. Zero Ads. Zero Subscriptions.
All tools built by Outlayer Labs are permanently free to download and use with zero advertising, zero subscription paywalls, and zero cloud lock-in.
Decibel processes all data in local sandboxed memory.
Read the complete legal verification and hardware permissions audit detailing on-device execution.