Wave per unit distance (typically per meter), can be associated with the wavelength by the relation The period formula_33 is the time for one complete cycle of an oscillation of a wave. The frequency formula_34 is the number of periods per unit time (per second) and is typically measured in hertz denoted as Hz. These are related by: In other words, the frequency and period of a wave are reciprocals. The angular frequency formula_28 represents the frequency in radians per second. It is related to the frequency or period by The wavelength formula_30 of a sinusoidal waveform traveling at constant speed
Critical distance Critical distance Critical distance is, in acoustics, the distance at which the sound pressure level of the direct sound D and the reverberant sound R are equal when dealing with a directional source. In other words, it is the point in space at which the combined amplitude of all the reflected echoes are the same as the amplitude of the sound coming directly from the source (D = R). This distance, called the critical distance formula_1, is dependent on the geometry and absorption of the space in which the sound waves propagate, as well as the dimensions and shape of