Wavelet Voice Sonogram

"Wavelet Voice Sonogram is a new sound spectrogram app that performs time-frequency analysis of acoustic signals.

A spectrogram is a graph that shows the results of a sound frequency spectrum analysis with time on the horizontal axis, frequency on the vertical axis, and signal strength in colors.

This app can perform acoustic analysis and display the spectrograms by using three time-frequency analysis methods, Wavelet analysis, Octave Band analysis, and FFT analysis.

It can record sounds from iPhone built-in microphone. While playing the sound, you can search for the desired sound and analyze it.

This app allows you to easily perform acoustic analysis of speech, instrumental sounds, noise, and more. It can also be used to learn elementary speech analysis.

Features:
- Acoustic analysis can be performed using PCM data recorded with the iPhone's built-in microphone. It is possible to analyze 5 seconds of sound data backward from a user-specified point in time.
- Three types of acoustic analysis, FFT analysis, octave band analysis and wavelet analysis, can be performed simultaneously.
- PCM sound recording and playback is possible up to about 180 seconds, and the audio waveform graph and FFT analysis graph are displayed. While playing back sound, you can search for sound at any point in time.
- You can zoom in on a specific 10 seconds of PCM data and play back the sound. It can be used to find the sound at the point you want to analyze.
- The spectrogram analysis result and time axis waveform can be contrasted and played back.

Specifications:
- Sampling frequency: 48 kHz
- PCM recording time: approx. 180 seconds max.
- Sound zoom function (10-Sec): Zooms in on any 10 seconds of PCM data and plays back the sound.
- Acoustic Analysis: About 5 seconds (Analysis points can be specified using the Time position slider.)
　FFT analysis (FFT): FFT 2048 points
　Octave band analysis (OCT): 1/48 octave band
　Wavelet analysis (DWT): Gabor Wavelet
- Sound recording and playback, sound waveform and FFT graph display (Main): PCM graph, 10sec zoom graph, FFT graph.
- Time position slider: Points to the cursor position on PCM graph.
- Spectrogram display (FFT / OCT / DWT): 5 sec PCM graph and spectrogram analysis graph (vertical axis - time [0 - 5.0 sec], horizontal axis - frequency [100Hz - 8kHz])
- Snapshot (Snap): Save the analysis image in "Photos".

Notes:
- The authorization for access to the built-in microphone will be confirmed by the iOS system at first boot. Please enable access to the microphone.
- The analysis time varies greatly depending on the performance (generation) of your iPhone. It may take about 5 to 20 seconds.
- Wireless (Bluetooth) headphones and headsets are not supported.