# What are periodic and aperiodic signals

Periodic - Aperiodic

Here you will find examples of periodic and aperiodic waveforms.

By definition, a periodic signal shape repeats itself after a certain time T, that is, it has a regular structure. T is called the period. The reciprocal value f = 1 / T corresponds to the fundamental frequency of the signal and is therefore decisive for the perceived pitch.

Aperiodic signal forms, on the other hand, do not have a regular pattern. The period duration and basic frequency can therefore not be determined. Aperiodic signal forms do not lead to a clear perception of pitch and are perceived as noises.

Project

Record various sounds and noises with a microphone. Load this into an audio editor of your choice and view the waveform.
Try to divide your recordings into periodic and aperiodic signals.
What difficulties do you see in doing this?
Try to determine the period T or the fundamental frequency f = 1 / T of the periodic signals.

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