And sound manufacturers have understood acoustic principles
Principle of horn sound
An important part of the sound system is the speaker, which is usually composed of a speaker unit and a box. The speaker unit ACTS as a sounding part, and the cabinet ACTS as a complement to the speaker unit to correct the sound. Sound principle of speaker unit is a kind of electrical energy into sound a transformation, when different electron energy to coil, coil produces a kind of energy with magnet magnetic field interaction, paper plates, vibration caused by the interaction because the electron energy at any time change, loudspeaker coil will forward or backward movement, so the speaker paper plates will follow movement, this action changes in terms of the air and produce sounds.
When a tree falls in the forest, it makes a loud noise, but no one is in the primeval forest, so it cannot be heard. Does that make a sound? What makes a sound is what it does, because when a tree trunk or a branch touches the ground, they make a sound that no one hears, but it makes a different sound to what a human or any other animal hears. So what makes a sound is what they call Psychoacoustics.
In 1915, there was an American named E. S. Electroacoustics was born when Pridham attached a telephone listener to a phonograph horn that played records for a crowd celebrating Christmas in San Francisco. After the end of world war I, in the United States President Harding (Harding) his inauguration, the telephone bell companies in the United States of moving coil to connect at the time of the horn on the record player, will be able to pass the sound to watch the inauguration of a large group of people, thus creates a lot of professional audio research and development the amplification engineering this science. Not only do audio researchers try to improve the sound equipment, but they also do different kinds of experiments to understand the human response to hearing. But the highest level of sound researchers all understand that acoustics is to study the whole, to understand every link of sound equipment, and human physiological response to hearing, they have made a great contribution.