Longitudinal wave and seismic P-waves (created by earthquakes and explosions). In longitudinal waves, the displacement of the medium is parallel to the propagation of the wave, and waves can be either straight or round. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. In the case of longitudinal harmonic sound waves, the frequency and wavelength can be described by the formula where: The quantity "x"/"c" is the time that the wave takes to travel the distance "x". The ordinary frequency ("f") of the wave is given by The wavelength
3D sound reconstruction field can be reconstructed as well. This method is applicable primarily to ultrasound and to lower sound pressures, often in water and in medical imaging. The method works under the assumption that the wave number of the medium is constant. If the wave number is changing throughout the medium, this method cannot reconstruct the three-dimensional sound field as accurately. 3D sound reconstruction 3D sound reconstruction is the application of reconstruction techniques to 3D sound localization technology. These methods of reconstructing three-dimensional sound are used to recreate sounds to match natural environments and provide spatial cues of the sound source. They