FFT analysis provides in-depth frequency-domain analysis capabilities for audio signals. Within a set recording period, the system slices and analyzes the acquired waveform according to the FFT length, with results updated dynamically in real time. Users can flexibly adjust core parameters such as FFT length, window function, averaging method and times based on testing requirements, and obtain multi-dimensional analysis results including FFT spectrum, ASD, and PSD. After the test is completed, functions including playback, audio listening, waveform and data export, and report generation are supported.