![]() ![]() For instance, the TWEETER of a loudspeaker is shaped in the form of a fan for this purpose. 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. Ĭompare: CANCELLATION, INTERFERENCE, PARABOLIC REFLECTOR, REFLECTION, REFRACTION. These effects also occur when a light wave travels through a medium with a varying refractive index, or when a sound wave travels through a medium with varying. Thus, diffraction may aid sound dispersion and DIFFUSION. For instance, in closed spaces a sound wave will encounter obstacles such as walls. In this chapter, we will consider how these properties are affected by the medium and the environment in which the wave propagates. Acoustic Diffusers are used to disperse reflections spatially. In chapter 1, we introduced the general properties of waves, such as wavelength, amplitude, speed and so on. 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. The higher-order the reflection, the further the wave has travelled and the later they arrive. 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. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |