Expand all + Pitch 3C20.10 - Range of Hearing 3C20.16 - Ultrasonic Bars 3C20.25 - Coke Bottles + Intensity and Attenuation 3C30.21 - Intensity vs. Distance + Wave Analysis and Synthesis 3C50.10 - Fourier Synthesizer 3C50.55 - Distinguishing Harmonics with the Ear 3C50.80 - Spectrum Analyzer + Music Perception and Voice 3C55.80 - Formants