An example of this property is the shadow. For instance, the TWEETER of a loudspeaker is shaped in the form of a fan for this purpose. diffraction, the spreading of waves around obstacles. What is Diffraction of LightDiffraction is the bending of light as it passes the edge of an object. Īs a result of their capability of diffraction, low frequency sounds are difficult to localize or contain in an environment (see CANYON EFFECT, DIFFUSE SOUND FIELD ).Īn acoustic radiator must be specially designed for good dispersion of high frequencies since this does not occur naturally through diffraction. Diffraction refers to the spreading of light around an obstacle. Ĭompare: CANCELLATION, INTERFERENCE, PARABOLIC REFLECTOR, REFLECTION, REFRACTION. Rachel and I briefly looked into the various diffraction patterns that arise from shining light through different shaped apertures: circular, square, and triangular, however our measurements and calculations focus on the square aperture. Refraction is also wavelength-dependent the amount of refraction increases if the wave with a shorter wavelength is incident on the medium. Thus, diffraction may aid sound dispersion and DIFFUSION. Light of wavelength is incident at an angle and diffracted by the grating (with a groove spacing dG) along a set of. The diffraction corresponds to the wavelength as the wavelength is more, the amount of diffraction will be more. When the wavelength is similar to the dimensions of the object, as with low frequencies and buildings, or mid-range frequencies and the head, the wave diffracts around the object, using its edges as a focal point from which to generate a new wavefront of the same frequency but reduced intensity. Diffraction of light plays a paramount role in limiting the resolving power of any optical instrument (for example: cameras, binoculars, telescopes, microscopes, and the eye). Low frequency sounds have wavelengths that are much longer than most objects and barriers, and therefore such waves pass around them undisturbed. Such is the case with high frequencies with respect to the head, and thus is important in BINAURAL HEARING. High frequency sounds, with short wavelengths, do not diffract around most obstacles, but are absorbed or reflected instead, creating a SOUND SHADOW behind the object. The phenomenon in SOUND PROPAGATION whereby a SOUND WAVE moves around an object whose dimensions are smaller than or about equal to the WAVELENGTH of the sound.
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