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The violin recording in particular clearly demonstrates the rich harmonic content for each note played (this appears on the spectrogram as multiple higher frequencies being generated for each fundamental frequency). You can stop the motion by clicking the pause button on the audio player. To view the spectrogram, choose your sound input, then click the play button and the graph will appear on the screen, moving from right to left. Additionally, you can upload your own audio files. Each of these has unique and interesting patterns for you to observe. The demo above allows you to select a number of preset audio files, such as whale/dolphin clicks, police sirens, bird songs, whistling, musical instruments and even an old 56k dial-up modem. The frequency spectrum is generated by applying a Fourier transform to the time-domain signal. This demo shows the signal represented in a different way: the frequency domain. In the oscilloscope demo, the plot shows the displacement of an audio signal versus the time, which is called the time-domain signal. In many ways, this demo is similar to the Virtual Oscilloscope demo, but there is a crucial and very important difference. You can toggle between a linear or logarithmic frequency scale by ticking or unticking the logarithmic frequency checkbox.
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The darker areas are those where the frequencies have very low intensities, and the orange and yellowĪreas represent frequencies that have high intensities in the sound. The resulting graph is known as a spectrogram. The spectrum analyzer above gives us a graph of all the frequencies that are present in a sound recording at a given time.
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