Sound diffraction strength depends on wavelength relative to opening size

Evidence

When the size of the wavelength is large relative to the opening, the wave is diffracted strongly, and when the wavelength is small relative to the opening, the diffraction is low. The transition between the wavelength being small and large with respect to the opening occurs when the opening size is about two thirds of the wavelength (2/3 λ). — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 426

Categorization

• corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 426