TheoMeter vs Sound Meter

TheoMeter helps you monitor sound levels, view live frequency spectrum activity, and document setup conditions from your iPhone. Designed for public-event and auditorium sound checks, TheoMeter combines a live dB meter with spectrum analysis tools, photo documentation, saved sessions, and exportable data. Use it to quickly understand room noise, monitor target levels, track peaks, and capture setup photos with optional dB overlays. Features include: -Live sound level meter with dBA, dBC, and dBZ weighting -Real-time frequency spectrum display -RTA bars, spline, and spectrogram views -Dominant frequency and selected band tracking -Fast, slow, and impulse response options -Leq, average, max, peak, and session duration stats -Dosimeter-style noise exposure view -Camera mode with sound-level overlay and filters -Save and export session data -Calibration offset controls -Clean navy, yellow, and white professional interface TheoMeter is ideal for sound technicians, event volunteers, venue setup teams, educators, presenters, and anyone who needs a clear view of sound levels and frequency behavior in a room. Note: TheoMeter uses the iPhone microphone for practical sound analysis. For compliance-grade measurements, use a professionally calibrated sound level meter.

A sound level meter for iPhone that is honest about what it does not know. Point your iPhone at a sound and it tells you how loud it is, in decibels, using the weightings and time constants a real sound level meter uses. Record a session and you get the statistics that matter afterwards — the energy average, the peak, the quietest moment — plus a CSV or PDF you can send to someone. EVERY PRO METRIC IS FREE Not a trial, not a teaser. The full measurement feature set is in the free version, and paying only removes the advertising. • LAeq — energy-average level • LCpeak — instantaneous peak • LAFmax and LASmin • A, C and Z frequency weighting • Fast and Slow time weighting • FFT spectrum with dominant frequency • Octave and 1/3-octave band analysis • Session recording, history and notes • CSV and PDF export MEASURE THE WAY YOU NEED TO Keep measuring with the screen locked. Watch the live trend. See what the noise compares to in plain words. Set a warning level and feel it rather than watch for it. THE HONEST PART This is not a certified sound level meter and it does not pretend to be. Readings are labelled Approximate in the app and in every export, because the absolute level rests on a provisional constant rather than a calibration measured against a reference instrument. Use certified equipment wherever a regulation requires it. When there is no measurable signal the reading is "--", not "0" — a covered microphone is not a quiet room. When measurement pauses, the number disappears rather than freezing at its last value. Connect a Bluetooth or USB-C microphone and the app says so, and refuses to apply a correction that was never measured for it. YOUR SOUND STAYS ON YOUR PHONE Audio and measurements are processed on your device without an account or upload to our servers. Microphone access is needed for measurement. The free version uses Google AdMob, which processes device and advertising information but does not receive your audio, measurements or recorded sessions. Advertising privacy choices and Apple tracking permission are handled separately. Requires iOS 17 or later. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/