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Transient Analyzer (Transient Response & Wavelet Analysis)

Transient Analyzer

Overview

A tool for detailed analysis of "transient sounds," such as instantaneous impact sounds or sounds whose frequency changes from moment to moment. It uses the Continuous Wavelet Transform (CWT) to visualize sounds while maintaining temporal resolution—capturing "when and at what pitch a sound occurred"—which is often difficult for standard FFT analysis to achieve.

Operation

Recording

  • Record: Pressing this button starts the recording. It stops automatically after acquiring data for the set Record Time.
  • Trigger: Like an oscilloscope, recording can be started at the moment a sound volume beyond a certain Level is detected.

Analysis

  • After recording is complete, press the Analyze button to perform the Wavelet Transform.
    • Note: This process is computationally intensive and may take several seconds to show results.

Reading the Charts

  • Transient Waveform (Top): The waveform of the recorded sound (Time axis).
  • Wavelet Scalogram (Bottom):
    • Horizontal axis: Time
    • Vertical axis: Frequency (Logarithmic display)
    • Color: Intensity at that moment.
    • Similar to a spectrogram, but it analyzes low-pitched sounds broadly in the time direction and high-pitched sounds sharply. This allows for a well-balanced simultaneous display of instantaneous click sounds (time information) and low hums (frequency information).

Settings

  • Wavelet: Selection of the waveform (mother function) type used for analysis. Generally, cmor (Complex Morlet) is suitable.
  • Min / Max Freq: Specifies the frequency range to be analyzed.

Use Cases

  • Impact Sound Analysis: Examining the response when a pulse is input to a speaker (impulse response) or changes in sound components when something collides.
  • Evaluation of Instrument Attack: Detailed observation of how harmonics appear at the moment a musical instrument starts sounding.