Sound Level & Spectrogram vs FNam FFT Spectrogram Analyzer

"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.

■ FNam FFT Spectrogram Analyzer Engineers need tools that are ready to use — anytime, anywhere. FNam FFT Spectrogram Analyzer turns your smartphone into a professional audio analysis tool. Unlike typical sound meter apps, it delivers advanced features like Dual File Comparison and CSV Export for precise post-analysis * completely free, no ads. Real-time FFT & Spectrogram / All processing runs on-device / No audio data uploaded externally. [Video Guide - See it in action] https://youtu.be/72SYLTG0l_8 ■ NEW FEATURES 1. Octave Band View Mode - Analyze sound levels by octave bands. - Choose 1/1 or 1/3 octave band resolution in Settings. 2. Sound Event Logger - Automatically logs sound events when the level exceeds a set threshold. - Can save event WAV files and FNam JSON logs for later review. - Includes a screensaver mode to reduce screen burn-in. ■ KEY FEATURES 1. Real-time Audio Analysis • High-precision FFT (Fast Fourier Transform) Graph. • Time Domain Waveform (Oscilloscope) view. • Fluid Spectrogram for visualizing frequency changes over time. 2. Dual File Comparison (Exclusive Feature) • Simultaneous loading of two WAV files for comparative analysis. • Spectrum Overlay: Visually compare differences using color-coded traces (Blue vs. Magenta). • Instant Calculation: Provides Arithmetic Mean and Mean Difference between signals. 3. Data Logging & Export • Flexible Sampling Rates: Supports various rates (4000Hz, 8000Hz, 16000Hz, 22050Hz, 44100Hz). • High-quality Recording: Audio is recorded and saved as WAV files, strictly matching the selected sampling rate. • Raw Data Export: Exports raw PCM data to CSV format. The exported data maintains the exact sampling rate and duration, making it optimized for post-processing in Excel, MATLAB, or Python. • File Management: Files are stored in the 'On My iPhone\FFT Analyzer' directory. - WAV naming format: Date_Time_SampleRate_Channel.wav ex) 20260219_164715_44100Hz_Mono.wav - CSV naming format: Selected WAV file name_SampleRate_Duration(s).csv ex) 20260219_164715_44100Hz_Mono_44100_5.2s.csv 4. Professional Configuration • Window Functions: Selectable Rectangular, Hann, Hamming, and Blackman windows. • Frequency Weighting: Supports A, B, C, and Z (Linear) standard weighting filters. • Axis Control: Supports both Auto-scaling and Manual range settings (Hz / dB) for precise graph inspection. • Calibration: Independent offset controls for FFT and Time Domain to ensure alignment with professional reference equipment. • Max Peak Hold: Displays and holds the maximum amplitude values across the frequency spectrum. • Octave Band View Mode: Visualizes frequency levels as octave band bars for easier band-by-band analysis. ■ TECHNICAL SPECIFICATIONS • Signal Processing: Anti-aliasing filters are automatically applied during downsampling to ensure measurement accuracy. • Sampling Rate: Supports standard rates up to 44.1kHz (device dependent). • Standards: Implements IEC 61672 frequency-weighting formulas for A/B/C weighting calculations. Note: This app implements IEC 61672 frequency-weighting formulas. Measurement discrepancies compared to professional equipment may occur due to the hardware frequency response limitations of the built-in smartphone microphone. For critical measurements, the use of a calibrated external microphone is recommended.