About Acoustics

Since ancient times, when the Greeks and Romans began formulating theories about sound waves, human beings have been fascinated by the science of sound. Acoustics, a branch of physics, is concerned with all aspects of sound, including its production, transmission and reception. While the study of music and musical instruments comprises one facet of acoustics, the fields of oceanography, seismology, medicine, architecture and engineering all utilize acoustics.

Ultrasound

• The use of ultrasonics, sound waves not audible to the human ear, has revolutionized medicine. As explained by acoustician Daniel Raichel, ultrasonics are used in ultrasound devices for both the diagnosis and treatment of patients. 3-D ultrasound is used by doctors to chart the progression of diseases in the body. Sonophoresis uses sound waves instead of needles to administer drugs such as insulin through the skin and acoustic hemostasis uses ultrasound to stop hemorrhaging. Doctors have also experimented with acoustical surgery, using sound instead of a scalpel to destroy benign or malignant tumors.

Noise Control

• Exposure to excessively loud music can damage hearing.

  The human ear is so sensitive, it can hear the sound of air particles bombarding the eardrum. It is no surprise, then, that repeated and prolonged exposure to noise can damage the ear. As scientist F. Alton Everest states, occupational and recreational noises can lead to permanent hearing loss. The agency responsible for creating noise effect guidelines is the Federal Interagency Committee on Noise or FICON. FICON issues guidelines regarding environmental noises such as railroads, road vehicles and highway construction projects. A separate agency monitors aircraft noise. OSHA, the Occupational Safety and Health Administration, establishes and enforces safety regulations, including noise exposure limits.

Underwater Acoustics

• Sonar helps submarines navigate underwater.

  Sonar, an acronym for sound navigation and ranging, is an important tool developed by underwater acousticians. There are two types of sonar, states expert Daniel Raichel. Passive sonar detects sound radiation and allows marine biologists to listen to whales and dolphins. Active sonar sends out a sound pulse and records the resulting echo. This type of sonar is used to find shipwrecks, map the ocean floor, detect icebergs below the surface and study fish migrations. Both types of sonar are used by the military in submarine navigation, underwater mine detection and communications.

Musical Acoustics

• Since acoustics is the science of sound and music is the art of sound, musical acoustics is the place where science and art truly meet. Musical acoustics encompasses a wide range of topics such as the manufacture of instruments, the voice as a musical instrument, note and scale relationships and the perception of music by the listener. A well-documented branch of musical acoustics is the study of violins made by Antonio Stradivari. Researchers have yet to discover why these instruments constructed in the 18th century are superior in sound to all others.

Architectural Acoustics

• Architecture and music combine when architects design concert halls, opera houses and recording studios. Properly designed concert venues eliminate sound defects like echoes and excessive loudness and enhance the clarity of sound for both audience members and performers. Architects follow acoustical principles in the construction of homes and factories, as well. Practical applications include insulating homes against outside environmental noise such as traffic and in factories, minimizing the noise of machinery in work spaces.