Earthworks is a professional audio equipment

Audio engineering

An audio engineer, also called audio technician, audio technologist or sound technician, is a specialist in a skilled trade that deals with the use of machinery and equipment for the recording, mixing and reproduction of sounds. The field draws on many artistic and vocational areas, including...

 company founded by David E. Blackmer

David E. Blackmer

David E. Blackmer was an American audio electronics engineer, most famous as the inventor of the DBX noise reduction system and founder of dbx, Inc.....

 in the late 1980s after he left dbx

Dbx, Inc.

dbx, Inc. is an American producer of professional audio recording equipment. It was founded by David E. Blackmer in 1971. The original company goal was: "To get closer to the realism of a live performance." Its early products were based on the concept of using decibel expansion which gave the...

 to sell studio microphone

Microphone

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...

s, preamplifier

Preamplifier

A preamplifier is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main...

s and studio reference monitors

Loudspeaker

A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

.

Their products are based on Blackmer's research into ultrasonic frequencies

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

 in sound reproduction and his claims that the time resolution of human hearing is 5 microseconds or better - corresponding to 200 kHz, well above the 20 kHz conventionally accepted as the limit of human hearing

Hearing (sense)

Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...

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