mindmap root((SON)) sonic 1、 Having to do with sound.
2、 Having to do with the speed of sound in air （about 750 miles per hour）.
🌱A sonic depth finder can easily determine the depth of a lake by bouncing a sound signal off the bottom. 🌳A sonic boom is an explosive sound created by a shock wave formed at the nose of an aircraft. In 1947 a plane piloted by Chuck Yeager burst the "sound barrier" and created the first sonic boom. In the decades afterward sonic booms became a familiar sound to Americans. （Because of steps that were eventually taken, sonic booms are rarely heard anymore.） Today *sonic* is often used by ambitious rock musicians to describe their experimental sounds. dissonant 1、 Clashing or discordant, especially in music.
2、 Incompatible or disagreeing.
🌱Critics of the health-care plan pointed to its two seemingly dissonant goals: cost containment, which would try to control spending, and universal coverage, which could increase spending. 🌳Since *dissonant* includes the negative prefix *dis-*, what is dissonant sounds or feels unresolved, unharmonic, and clashing. Early in the 20th century, composers such as Arnold Schoenberg and his students developed the use of *dissonance* in music as a style in itself. But to many listeners, the sounds in such music are still unbearable, and most continue to prefer music based on traditional tonality. *Dissonant* is now often used without referring to sound at all. *Cognitive dissonance*, for example, is what happens when you believe two different things that can't actually both be true. resonance 1、 A continuing or echoing of sound.
2、 A richness and variety in the depth and quality of sound.
🌱The resonance of James Earl Jones's vocal tones in such roles as Darth Vader made his voice one of the most recognizable of its time. 🌳Many of the finest musical instruments possess a high degree of resonance which, by producing additional vibrations and echoes of the original sound, enriches and amplifies it. Violins made by the Italian masters Stradivari and Guarneri possess a quality of resonance that later violinmakers have never precisely duplicated. And you may have noticed how a particular note will start something in a room buzzing, as one of the touching surfaces begins to *resonate* with the note. Because of that, *resonance* and *resonate*—along with the adjective *resonant*—aren't always used to describe sound. For example, you may say that a novel resonates strongly with you because the author seems to be describing your own experiences and feelings. ultrasonic Having a frequency higher than what can be heard by the human ear.
🌱My grandfather's dog is always pricking up its ears at some ultrasonic signal, while he himself is so deaf he can't even hear a bird singing. 🌳*Ultrasound*, or *ultrasonography*, works on the principle that sound is reflected at different speeds by tissues or substances of different densities. Ultrasound technology has been used medically since the 1940s. *Sonograms*, the pictures produced by ultrasound, can reveal heart defects, tumors, and gallstones; since low-power ultrasonic waves don't present any risks to a body, they're most often used to display fetuses during pregnancy in order to make sure they're healthy. *Ultrasonics* has many other uses, including underwater *sonar* sensing. High-power ultrasonics are so intense that they're actually used for drilling and welding.