EchoMeter

EchoMeter is a fully offline Android app for approximate room sound decay estimates and before/after acoustic comparisons.

Important: EchoMeter is not a certified sound level meter and does not replace professional RT60 measurements. Results are meant for repeatable relative comparisons on the same device and at the same room position.

What you can do:
• Guided test flow with setup, measurement point selection, clap or safe test impulse, and a live level indicator
• PCM capture via microphone, local WAV saving, and WAV import through the system file picker
• RMS envelope, background dBFS, peak, SNR, approximate decay time, and quality score
• Automatic rejection of clipping, weak signal, high background noise, and insufficient SNR
• Room profiles, measurement point layout, and test history
• Compare two accepted tests from the same point with a relative improvement percentage
• Local recommendations based on room shape, size, purpose, and the latest test
• Export analysis to PDF and room layout to PNG
• Versioned JSON backup with validation plus merge/replace strategies
• Light/dark theme, Dynamic Color, metric and imperial units, onboarding, and search

Privacy:
• No backend, accounts, analytics, ads, or in-app purchases
• No INTERNET permission — data never leaves the device
• RECORD_AUDIO is requested only right before recording