Audible frequency range determines wavelength ratio

Steps:

• Human ear detects frequencies from 20 Hz (lowest) to 20,000 Hz (highest).
• Sound wavelength λ = v / f, where v (speed of sound) is constant at ~343 m/s.
• Longest wavelength λ_max occurs at 20 Hz; shortest λ_min at 20,000 Hz.
• Ratio λ_max / λ_min = f_max / f_min = 20,000 / 20 = 1,000.

Why B is correct:

• Wavelength ratio equals inverse frequency ratio per wave equation λ = v / f, yielding 1,000:1 for 20 Hz to 20 kHz range.

Why the others are wrong:

• A: 20:1 matches frequency range in Hz but ignores inverse for wavelengths.
• C: 10,000:1 overestimates by misapplying 20 kHz / 2 Hz.
• D: 20,000:1 equals raw frequency span, not wavelength ratio.

Final answer: B