Sound Spectrography can make sound signals into a visible spectrogram. We can observe from the spectrogram the frequency of the sound signal, amplitude and time of physical parameters, and the dynamic relationship among them,then we can understand the nature of the measured acoustic signals. Using the Sound Spectrography we can not only clarify abnormal voice part of the structure, strength, but also can we observe the transient of voice, in another word, we can "see" the sound. Sound image and the combination of clinical examination, can provide a meaningful theoretical basis for diagnosis and objective evaluation of cleft palate speech and speech training.
In this paper, a spectrogram based on PC is presented by using the idea of Virtual Instrument (VI) and the Short Time Fourier Transform (STFT) , design principle of the spectrogram is discussed, the affection between different parameters and programming realization are also analysed. At last, test and application indicate the good function.
Keywords: Sound Spectrography, time frequency analysis, spectrogram, STFT
