Experiment: Audio Spectrum

From phyphox
Jump to navigation Jump to search
Audio Spectrum
Experiment Audio Spectrum
Category Acoustics
Used sensors Microphone

The experiment "Audio Spectrum" displays the frequency spectrum as well as the peak frequency of an audio signal recorded with the microphone.


There are no hardware requirements. The microphone is used to measure any sound. However, depending on your requirements you might want to attach an external microphone to your device.


There is no specific setup. Depending on what audio source you want to measure, you might want to aim the microphone at the sound source and try to damp the sound from the environment.


This experiments records audio in blocks of about 170ms (8192 samples) and calculates the (discrete) Fourier transform of the audio signal, which is displayed. The peak frequency is the frequency of the maximum of the Fourier transform.

Problems and resolutions

  • The frequency resolution is too low. The frequency resolution is limited by the length of the recording (170ms). You can either try the Audio Autocorrelation experiment (if your audio signal only consists of a single frequency) or you can use the experiment editor to load this experiment and increase the recording period.