Sound and frequencies: Science KS3 - Lesson 3
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Science KS3 Lesson 3: Sound and frequencies
Screen 2: The team detects the harbour porpoise clicks using a hydrophone that is towed behind the boat. The hydrophone has a sound-detecting element inside a liquid filled tube. The liquid needs to be a suitable medium so that sounds can travel from the seawater to the hydrophone efficiently.
Screen 4.1: This chart is a blank power spectrum (a visual representation of the frequencies in sound as they vary with time). What might the units be for the x and y axes?
Screen 4.2: The x axis displays the frequency of the sound in kilohertz (kHz). The y axis displays the amplitude (the volume) of the different frequencies in decibels (dB). Where would sounds within the human range of hearing appear in the spectrum?
Screen 4.3: The human ear can hear sounds up to 20,000 Hz (i.e. 20 kHz).