Timbre Determines Waveform Shape

Steps:

• Recall that timbre is the quality distinguishing sounds of same pitch and volume, due to harmonic content.
• Understand oscilloscope displays sound as voltage vs. time trace, representing pressure waves.
• Identify that pitch relates to frequency (repetition rate), volume to amplitude (height), but timbre to unique waveform pattern.
• Conclude the trace feature varying with timbre is its overall shape.

Why C is correct:

• Timbre arises from the waveform's shape, as defined by the mix of fundamental and harmonic frequencies in the sound wave.

Why the others are wrong:

• A: Amplitude affects loudness, not timbre.
• B: Frequency determines pitch, independent of sound quality.
• D: Wavelength is inversely related to frequency via λ = v/f, so ties to pitch, not timbre.

Final answer: C