Sound Level Meter: Decibel

Measure noise like a pro — straight from your iPhone.

Sound Level Meter: Decibel turns your iPhone into a precision SPL meter, engineered to the IEC 61672-1 international standard. Protect your hearing, document a noise complaint, tune a studio, or pre-check a workplace - reliable readings in seconds, clean A4 PDF reports in one tap.

KEY FEATURES

• Real-time dB readings with A, C and Z weighting — switch on the fly
• Fast (125 ms), Slow (1 s) and Impulse time integration — the modes pros use
• 1/3-octave frequency analysis
• Multiple live visualizations: histogram, gauge, circle meter, applause meter, basic graph
• All metrics in one place: LAeq, Min, Max, Avg, Peak
• Save full measurement sessions with timeline, location and notes
• Calibration screen for fine-tuning against any reference meter
• Available in English, French, German, Spanish, Italian, Japanese, Chinese
• Distraction-free dark interface focused entirely on your data

DESIGNED FOR ACCURACY
Sound Level Meter: Decibel follows the IEC 61672-1 sound level meter specification:
• True biquad-cascade A and C weighting filters — not generic high/low-pass approximations
• Exponential averaging on squared pressure (the correct method)
• Per-device calibration based on the iPhone hardware actually in use
• User-adjustable offset to align with any reference meter or calibrator

IDEAL FOR
• Audio engineers tuning studios, venues and rehearsal spaces
• Workplace safety pre-checks before a formal acoustic survey
• Musicians, DJs and podcasters watching their hearing exposure
• Parents monitoring nursery or kids' bedroom noise levels
• Tenants documenting noise from neighbors, traffic or construction
• Anyone serious about long-t