Electrical signal in the context of "Electrical noise"

Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear. Headphones are also known as earphones or, colloquially, cans. Circumaural (around the ear) and supra-aural (over the ear) headphones use a band over the top of the head to hold the drivers in place. Another type, known as earbuds or earpieces, consists of individual units that plug into the user's ear canal; within that category have been developed cordless air buds using wireless technology. A third type are bone conduction headphones, which typically wrap around the back of the head and rest in front of the ear canal, leaving the ear canal open. In the context of telecommunication, a headset is a combination of a headphone and microphone.

Headphones connect to a signal source such as an audio amplifier, radio, CD player, portable media player, mobile phone, video game console, or electronic musical instrument, either directly using a cord, or using wireless technology such as Bluetooth, DECT or FM radio. The first headphones were developed in the late 19th century for use by switchboard operators, to keep their hands free. Initially, the audio quality was mediocre and a step forward was the invention of high fidelity headphones.

A microphone, colloquially called a mic (/maɪk/), or mike, is a transducer that converts sound into an electrical signal. Microphones are used in telecommunication, sound recording, broadcasting, and consumer electronics, including telephones, hearing aids, and mobile devices.

Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; the condenser microphone, which uses the vibrating diaphragm as a capacitor plate; and the contact microphone, which uses a crystal of piezoelectric material. Microphones typically need to be connected to a preamplifier before the signal can be recorded or reproduced.

An electric guitar is a guitar that requires external electric sound amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickups to convert the vibration of its strings into electrical signals, which ultimately are reproduced as sound by loudspeakers. The sound is sometimes shaped or electronically altered to achieve different timbres or tonal qualities via amplifier settings or knobs on the guitar. Often, this is done through the use of effects such as reverb, distortion and "overdrive"; the latter is considered to be a key element of electric blues guitar music and jazz, rock and heavy metal guitar playing. Designs also exist combining attributes of electric and acoustic guitars: the semi-acoustic and acoustic-electric guitars.

Invented in 1932, the electric guitar was adopted by jazz guitar players, who wanted to play single-note guitar solos in large big band ensembles. Early proponents of the electric guitar on record include Les Paul, Eddie Durham, George Barnes, Lonnie Johnson, Sister Rosetta Tharpe, T-Bone Walker, and Charlie Christian. During the 1950s and 1960s, the electric guitar became the most important instrument in popular music. It has evolved into an instrument that is capable of a multitude of sounds and styles in genres ranging from pop and rock to folk to country music, blues and jazz. It served as a major component in the development of electric blues, rock and roll, rock music, heavy metal music and many other genres of music.

In electronics, noise is an unwanted disturbance in an electrical signal.

Noise generated by electronic devices varies greatly as it is produced by several different effects.

A preamplifier, also known as a preamp, is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier and a loudspeaker. Without this, the final signal would be noisy or distorted. They are typically used to amplify signals from analog sensors such as microphones and pickups. Because of this, the preamplifier is often placed close to the sensor to reduce the effects of noise and interference.