A lavalier microphone or lavalier (or lav or lapel mic) is a small electret or dynamic microphone used for television, theatre, and public speaking applications, in order to allow hands-free operation. They are most commonly provided with small clips for attaching to collars, ties, or other clothing. The cord may be hidden by clothes and either run to a radio frequency transmitter in a pocket or clipped to a belt (for mobile work), or directly to the mixer (for stationary applications).

These miniature microphones are often supplied with a choice of push-on grilles of differing lengths that provide gentle high-frequency boost by forming a resonant cavity. A peak of approximately 6 dB at 6-8 kHz is considered beneficial for compensating loss of clarity when chest-mounted, and a peak of a few decibels at 10–15 kHz when mounted in the hair above the forehead. This method of boosting high frequencies does not worsen noise performance, as electronic equalization would do.

History

An American electronics engineer with Educational Media Resources and San Jose State College, Raymond A. Litke, invented the wireless microphone in 1957 to meet the multimedia needs for television, radio, and classroom delivery. His U.S. Patent No. 3,134,074, filed May 6, 1961, (originally filed January 8, 1960) is for the first portable, workable, practical, and dependable wireless microphone. The patent's diagram illustrates a cigar-sized device which was six inches long and weighed seven ounces, including a power supply and transmitter. Impressed by the more than one-half-mile distance of transmission, the FCC granted Litke 12 frequencies at his approval hearing. Litke coined the term "lavalier microphone," a word which appears in his patent.

Also called the Vega-Mike, after Vega Electronics Corporation which first manufactured it in 1959, Litke's midget device (both hand-held and lavalier) was used by the broadcast media during the 1960 Democratic and Republican National Conventions. It allowed television reporters to roam the floor of the convention to interview participants where Presidential candidates Kennedy and Nixon were the first celebrities to use the wireless microphone. The American Broadcasting Corporation (ABC) completed testing in 1959, prior to the conventions. Television anchor John Daly was exuberant with his praises for Litke's invention on the television news in July 1960. The wireless microphone was also tested at the Olympic trials held at Stanford University in 1959.

In newspaper articles from both the San Jose News of September 10, 1960, and The Alma Signal-Enterprise (KS) dated November 10, 1960 and February 26, 1981, Litke attributes the inspiration of his invention to the winged communication of the bee. Although electronics experts and scientists told him the wireless microphone was an impossibility, Litke managed to invent the microphone in 1957. This wireless microphone was only one of Litke’s inventions. In the 1960s, Litke was employed at University of California Medical Center in San Francisco where he invented several medical instruments, including the fiber-optic colonoscope.

Mounting techniques

In television and documentary applications, the lavalier will typically be clipped to the subject's clothing, such as a tie, jacket or collar. In narrative motion picture usage, lavs are almost always hidden under clothing to conceal the fact that the person is mic'ed. The Boom microphone typically sounds 'better', more natural than a lavalier mic and is always a soundman's first choice, however oftentimes for exterior location shooting, it may be more practical to use a lavalier. One such situation would be during a wide shot that forces the boom operator to keep a distance with his microphone from the speaking talent that isn't close enough to achieve a good signal to noise ratio. In that instance a lav mic hidden on the talent due to its proximity can achieve good signal to noise ratio for recording of speech. When lavalier microphones need to be concealed under clothing, the possibility of material scratching against the microphone is a certain risk. To minimize this, sound recordists might wrap the head of the microphones in moleskin or place it inside a hollow centered column-shaped sponge and place it under a placard, behind a button, or within the knot of a tie. The transmitter pack which the microphone is attached to may also need to be hidden under a person's clothing. Transmitter pouches are held on with elastic straps and hold the transmitter in various places, hidden wherever the clothing provides a non revealing space, i.e. high around the waist in the space created at the spine just above the belt line, inside the thigh under a skirt or dress, about the ankles under a pant leg, or even on the inside of a boot.

Manufacturers

References

Category:Microphones