Chambers 20th Century Dictionary(0.00 / 0 votes)Rate this definition: Sibilance. sibâ²i-lans, n. a hissing soundâalso Sibâ²ilancy.âadj. Sibâ²ilant, making a hissing sound.ân. a sibilant letter, as s and z.âv.t. Sibâ²ilÄte, to pronounce with a hissing sound.ân. SibilÄâ²tion, a hissing sound.âadjs.
Definition: A delta wave is a type of high amplitude brain wave found in humans. Delta waves have a frequency from one to four hertz and are measured using an electroencephalogram (EEG). These brain waves are thought to emerge from the thalamus and are generally associated with slow-wave sleep (during stages three and four of the stages of sleep.
A mechanical wave is a disturbance that pulsates through some form of medium: a solid, a liquid, or a gas, carrying the original, initiating energy from one place to another.There are three types of mechanical waves: transverse, longitudinal, and boundary.or a transverse waves, the amplitude is the distance that the wave displaces the medium. The number of waves passing through the medium over time is the waveâs frequency. The higher the frequency of a mechanical wave, the greater the energy it transmits.