Waves in the ocean travel through the water. Waves in the desert travel through the sand. Sound waves travel through the air. Have a student help you demonstrate this with the Slinky. Have them demonstrate and identify the parts of the wave.
Frequency relates to pitch.
A high note or sound has a higher frequency than a lower note or sound. Use the waveboard to demonstrate changes in frequency. Amplitude determines loudness or softness. Use the waveboard to demonstrate changes in amplitude. Amplitude can also be demonstrated by striking the tuning fork and moving the oscilloscope microphone closer and farther away.