Sound Level & Spectrogram vs Spectrum Analyzer+ Audio FFT

"Sound Level & Spectrogram" is a sound level meter app for iPhone to easily measure the sound level of noise and music in your living environment. Simply tap the start button to measure sound levels in decibels (dB) and view the real-time variation of the sound level. You can also use the spectrogram feature to visually check the frequency characteristics of the sound source. Furthermore, you can select between frequency weighting correction characteristics and time weighting characteristics, which are essential for standard sound level meters, enabling appropriate sound measurement. Exposure to noise can impact health, potentially causing tinnitus, sleep disorders, stress, cognitive decline and heart disease. These risks have also been highlighted by the World Health Organization (WHO). Understanding noise levels is the first step towards improving your quality of life. Use this app to protect your health and create a comfortable living environment. Features: - Sound level measurement (dB): Leq (equivalent sound level), Min (minimum value), Max (maximum value), Avg (time-averaged equivalent sound level) - Frequency weighting correction characteristics: A (general sound level measurement with auditory correction), C (sound level measurement with almost flatter correction than A correction, e.g. peak evaluation at high volume), Z (flat characteristics without auditory correction, physical sound level measurement) - Time weighting characteristics: Fast=0.125sec, Slow=1.0sec - Time course graph - Spectrogram: 1/3 octave band analysis - Measurement time: 20 sec Applications: - Environmental noise measurement - Architectural acoustics - Live sound check - Installation of audio equipment - Tuning of sound equipment - Device management Example of the noise level situation: - 130 dB: Engine sound of Airplane - 110 dB: Horn of Car - 100 dB: Noise of passing train - 90 dB: In loud factory - 80 dB: In the train, Vacuum cleaner - 70 dB: Noisy office, Noisy Street - 60 dB: Quiet Car, Normal conversation - 50 dB: Quiet office - 40 dB: In the library, Quiet residential area - 30 dB: Outskirts of midnight, Whisper - 20 dB: Sounds of rubbing leaves Note: - Spectrogram is a tool to analyze the frequency spectrum of sound, with time on the horizontal axis, frequency on the vertical axis, and the strength of the signal represented by colors, and is used for acoustic analysis, voiceprint identification, etc. - This app is adjusted the reference value for iPhone. However, the built-in microphone of your iPhone is likely to have a non-uniform gain. Therefore, exact measurements are not guaranteed. - The standard noise measurement range is 30-130 dBA, and the measured value (Leq) is about 30 dBA in a quiet room of the household. Due to the presence of background noise, noise levels are never measured at 0dBA even in very quiet environments. In a typical anechoic room, the noise level is around 5-15 dBA. - At the initial startup after installing the app, the iOS system asks for permission to access the built-in microphone. In this case, you need to enable access to the microphone. If you have not enabled this setting, this app cannot work by privacy restrictions of the iOS system. Please enable the access permission on the iOS setting, "Settings > Privacy & Security > Microphone". Please visit our iOS app support page for more information on this app.

Spectrum Analyzer+ Audio FFT shows the live frequency spectrum of any sound your iPhone microphone hears, then lets you capture a 5-second average and read the result: the strongest frequency in Hz, the top components and where the energy sits. ▶ See the spectrum live • 32 bands from 20 Hz to 20 kHz, computed with a 2048-point FFT • Four views: Bars with peak hold, Line, Waterfall and Spectrogram • Peak frequency and peak level update as you listen • Min / Max traces in the Bars view, tap a bar for a cursor readout, freeze the display to study it • Adjustable dB range from 30 to 120 dB ▶ Capture 5 seconds, get an answer Tap Capture 5 s under the graph and hold the sound steady. The app power-averages the spectrum over five seconds and shows a result card: • Strongest component in Hz, with the musical note and cents in Voice mode • Up to three top components with their levels • Share of the detected energy in the low, mid and high part of the selected range • Strongest band level and the FFT resolution of the measurement If the sound is too quiet in that range, the card says so instead of inventing a peak. ▶ Compare before and after Save a capture as a reference (up to 10). Make a change — move a speaker, add treatment, adjust a machine — capture again in the same mode and the card shows the average band-level difference in dB. References can also be overlaid on the live spectrum. ▶ Pick the job • Voice: 80–4000 Hz, shows the note of the strongest pitch • Machine: 20–2000 Hz, looks for 50/60 Hz mains hum and its harmonics • Room: 20–500 Hz, the low end where room modes build up ▶ Export and share • Export a CSV of the live spectrum or of a 5-second capture • Share a short text summary of a capture ▶ Extras • Calibration offset from −20 to +20 dB in 0.5 dB steps to line up with a reference meter • Pink noise generator, unlocked for 24 hours by watching a short ad • Interface in 30 languages ▶ Good to know Levels are relative to the microphone's full scale (dBFS). A phone microphone is not a certified sound level meter, so use the numbers to find frequencies and compare changes, not for compliance measurements. Audio is analysed in memory while you listen and is not saved as a recording. For musicians checking a tone, home studio and hi-fi owners chasing a boomy note, and anyone tracking down a hum from a fridge, fan or transformer.