3C10  The Ear
3C20  Pitch
            .10 Range of Hearing
3C30  Intensity and Attenuation
            .22 Sound Level Meter
3C40  Architectural Acoustics
3C50  Wave Analysis and Synthesis
            .10 Pasco Fourier Synthesizer
            .xx Clown Clicker
3C55  Music Perception and The Voice
            .55 Tuning Fork on Resonance Box