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Peak Frequency Example

In this video clip a detector is being used to find the peak frequency of an artificial ultrasonic signal produced from the black box.

The detector is first tuned well above the peak frequency and the note is very high pitched. As the detector tunes down towards the peak the pitch drops. At its very deepest point, the peak frequency, the frequency dial reads 38kHz.

As the detector carries on tuning down again the pitch gets higher again as it is moving farther away from the peak.

The box in this example is outputting a pure signal at 38kHz. Bats do not use pure frequencies like this but you can tune into the overall pitch in a similar way to find their peak frequency.


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