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Ludy
LudyMeter

Measure sound like a pro

Professional dB meter, FFT spectrum analyzer, musical note detection, and EU workplace safety tracking. The only sound meter that does it all.

dB Meter FFT Spectrum Note Detection EU Safety NIOSH / OSHA

iOS 17+ · iPhone · Free / Pro $14.99 / Safety $49.99 (lifetime)

LudyMeter real-time decibel meter with sound level display
LudyMeter FFT spectrum analyzer with frequency display
One-time purchase — no subscription EU workplace safety compliant Free tier included
Sound Level Meter

Know exactly how loud it is.

Real-time A-weighted decibel measurement with min, max, and average tracking. Everyday sound comparisons tell you if it's "as loud as a vacuum cleaner" or "hearing damage risk after 2 hours."

  • A, C, and Z frequency weighting
  • Fast, Slow, and Impulse time constants
  • 7-day measurement history (free)
LudyMeter decibel meter with real-time sound level measurement
LudyMeter FFT spectrum analyzer and octave band display
Spectrum Analyzer

See every frequency.

4096-point FFT with 1/1 and 1/3 octave band display. Musical note detection identifies A4, E3, Bb2 with cent-level precision. Compare before/after with A/B measurement snapshots.

  • Real-time FFT spectrum display
  • 1/1 and 1/3 octave bands (IEC 61260-1)
  • Musical note detection with ±0.5 cent accuracy

Everything included

Professional sound measurement without the professional price tag.

Real-Time dB Meter

A-weighted decibel measurement with min, max, and average tracking. Everyday sound comparisons help you understand readings.

Frequency Analyzer

Real-time FFT spectrum, 1/1 and 1/3 octave bands, and musical note detection with cent accuracy. Pro feature.

EU Safety Tracking

First iOS app with EU Directive 2003/10/EC noise exposure. LEX,8h, LCpeak, dose tracking, and PDF reports. Safety tier.

Note Detection

Translates frequency peaks into musical notes (A4, E3, Bb2) with cent deviation. Perfect for musicians and sound engineers.

Calibration System

Three-tier calibration: automatic device profiles, single-point reference calibration, and external .cal file support.

Privacy First

Zero data collection. Zero analytics. Audio processed entirely on-device and never recorded or transmitted.

See it in action

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Simple pricing

Three tiers. All one-time. No subscriptions.

Free

$0
  • Real-time dB meter (A-weighted)
  • Min / Max / Average tracking
  • 7-day measurement history
  • Sound comparison cards
POPULAR

Pro

$14.99 lifetime
  • Everything in Free
  • FFT spectrum • Octave bands
  • Musical note detection
  • Unlimited history • CSV export

Safety

$49.99 lifetime
  • Everything in Pro
  • EU Directive 2003/10/EC tracking
  • NIOSH • OSHA dosimeter
  • Background monitoring • PDF reports

Questions

How accurate is LudyMeter?

LudyMeter uses AVAudioEngine in measurement mode (no AGC, no noise suppression) for maximum accuracy. The three-tier calibration system includes automatic per-device offset profiles. While it doesn't replace certified Class 1/2 meters for legally binding assessments, it provides professional-grade screening accuracy.

What does the Safety tier include?

EU Directive 2003/10/EC compliance: LEX,8h (daily noise exposure normalized to 8 hours), LCpeak monitoring, real-time dose percentage, three-zone warnings at 80/85/87 dB(A), haptic alerts, background monitoring, and PDF screening reports. Also includes NIOSH and OSHA dosimeter modes.

Is this a one-time purchase?

Yes. Free tier gives you a real-time dB meter with 7-day history. Pro ($14.99) unlocks the frequency analyzer, note detection, and unlimited history. Safety ($49.99) adds EU/NIOSH/OSHA noise exposure tracking. Both are one-time purchases — no subscriptions.

Can it detect musical notes?

Yes. The Pro tier includes YIN-based pitch detection that identifies notes like A4, E3, or Bb2 with +/-0.5 cent accuracy. Great for tuning, room acoustics analysis, and identifying frequency sources.

Does it work in the background?

The Safety tier supports full-shift background monitoring for workplace noise exposure tracking. You don't need to keep the screen on — LudyMeter continues measuring and tracking your noise dose.

Start measuring sound today

Download free from the App Store. Get professional sound measurement in seconds.