Equipment for dealing with sound

Equipment for outputing or generating : musical instrument, sound box, hearing phones, sonar systems, sound reproduction, and broadcasting equipment. Many of these use electro-acoustic transducers for input : microphones .principle, any object that produces sound can be a musical instrument—it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the beginnings of human culture. The purpose of early musical instruments was ritual:[citation needed] a hunter might use a trumpet to signal success on the hunt, or a shaman might use a drum in a religious ceremony. Cultures later developed the processes of composing and performing melodies for entertainment.[citation needed] Musical instruments evolved in step with changing applications. The date and origin of the first device considered a musical instrument is disputed. The oldest object that some scholars refer to as a musical instrument, a simple flute, dates back as far as 67,000 years. Consensus begins to form about early flutes dating to about 37,000 years old. However, most historians believe that determining a specific time of musical instrument invention is impossible due to the subjectivity of the definition and the relative instability of materials that were used in their construction. Many early musical instruments were made from animal skins, bone, wood, and other non-durable materials. Musical instruments developed independently in many populated regions of the world. However, contact among civilizations resulted in the rapid spread and adaptation of most instruments in places far from their origin. By the Middle Ages, instruments from Mesopotamia could be found in Maritime Southeast Asia and Europeans were playing instruments from North Africa. Development in the Americas occurred at a slower pace, but cultures of North, Central, and South America shared musical instruments. By 1400, musical instrument development slowed in many areas and was dominated by the Occident.

he classification of musical instruments is a discipline in its own right, and many systems of classification have been used over the years. One may classify musical instruments by their effective range or their material composition; however, the most common method, Hornbostel-Sachs, uses the means by which they produce sound. The academic study of musical instruments is called organology.A sound box or sounding box (sometimes written soundbox) is an open chamber in the body of a musical instrument which modifies the sound of the instrument, and helps transfer that sound to the surrounding air. Objects respond more strongly to vibrations at certain frequencies, known as resonances. The chamber's own resonances supply the reinforcement, and so the tone quality and resonances of the instrument are altered as a whole wherever the chamber's resonances mismatch the chamber-less instrument's. The sound box typically adds resonances at lower frequencies, enhancing the lower-frequency response of the instrument. The distinctive sound of an instrument with a sound box owes a lot to the alteration made to the tone. A sound box is found in most string instruments.[1] The most notable exceptions are some electrically amplified instruments like the solid body electric guitar or the electric violin, and the piano which uses only a sound board instead. Drumhead lutes such as the banjo or erhu have at least one open end of the sound box covered with animal skin (or a skin-like acrylic material). Open back banjos are normally used for clawhammer and frailing, while those used for bluegrass have the back covered with a resonator. In some arrangements, loudspeakers also are mounted on a sound box to enhance their output, particularly bass speakers. One notable example of this arrangement is called the bass reflex enclosure. However, in these cases the box resonance is carefully tuned so as to make the sound more equal across frequencies, rather than to impart a particular character to the reinforced sound.