Frequency Analyzer: dB Meter

Calibrated SPL readings, scrolling spectrograms, NIOSH and OSHA dose tracking, reference tones, and PDF exposure reports. Analyze sound clearly on iPhone in the field.

Turn your iPhone into a calibrated sound level meter, spectrum analyzer, and noise dosimeter. Built for fieldwork, inspections, and everyday measurements.

Whether you are tuning a room, surveying noise on a job site, or checking workplace exposure, Frequency Analyzer gives you the data you need.

REAL-TIME SOUND LEVEL METER

• Live SPL readout with A, C, and Z weighting plus linear response
• Fast (125 ms), Slow (1 s), and custom time averaging
• Min, max, average, peak, and LAeq displayed continuously
• Configurable reference calibration so your readings match a known source

SPECTRUM AND SPECTROGRAM

• Real-time FFT spectrum from 20 Hz to 20 kHz, linear or logarithmic axis
• Scrolling spectrogram with selectable colormap and peak-hold markers
• Octave-band view at 1/1, 1/3, 1/6, or 1/12 resolution
• Classic oscilloscope waveform with adjustable time window
• Amplitude-over-time history for slow trends across hours

NOISE DOSIMETER

Track noise exposure against NIOSH and OSHA criteria or a custom standard you define. The app accumulates dose throughout your shift, projects your 8-hour exposure, and reports the time-weighted average. Add event notes and export a PDF report with stats and graphs.

REPORTS AND EXPORT

• Reference tone generator from 20 Hz to 20 kHz for signal checks
• CSV time-series exports for spreadsheets and analysis tools
• Spectrogram PNG snapshots at configurable resolution
• PDF reports with session statistics, charts, and event markers
• Calibration and preferences stored locally on your device

PRIVATE BY DESIGN

Everything runs on your device. There is no account, no login, and microphone audio does not leave your phone. Sessions, notes, calibration data, and preferences stay in local storage.

HOW TO USE

1. Grant microphone access and run the quick calibration walkthrough
2. Choose Analyzer, dB Meter, or Dosimeter from the tab bar
3. Use spectrum, spectrogram, waveform, octave, or amplitude history
4. Watch dose, peak, average, and frequency readings as you measure
5. Export CSV, PNG, or a PDF report when you need results

Built for acousticians, safety officers, HVAC inspectors, musicians, and students who want serious acoustic measurement in their pocket.

Free to download. Some features require a premium purchase. Privacy Policy: https://estifie.com/apps/frequencyanalyzer/privacy-policy Terms of Use: https://estifie.com/apps/frequencyanalyzer/terms-of-use