1) The low-frequency pitch that occurs when power line current is accidently induced or fed into electronic equipment. The hum reflects the fundamental frequency of the current (60 Hz in the U.S., and 50 Hz in many European countries). 2) To vocalize a pitch without opening one’s mouth.
A variation of the cardioid microphone pick up sensitivity pattern in which the shape of the optimal pickup area is tighter and more directional than cardioid. Hypercardioid microphones are most sensitive directly on-axis in front of the microphone, and begins rejecting sounds between 90-150 degrees off-axis, depending on the tightness of the pattern.
An abbreviation for the term Hertz, or the unit of frequency.
An abbreviation for “Input/Output.” In audio, it refers to any device, program or system involving the transferring of electrical/audio signals or data.
See “Integrated Circuit.”
See “Intermodulation Distortion.”
Refers to the ability to localize a specific sound within the sound space. In recording environment, it refers to “placing” instruments within the stereo or surround field so that it when the sound is played through speakers, it fools our ears into thinking the sound source is in emanating from a specific point instead of from the speakers. In live audio and sound reinforcement, the principle of imaging is the same, the goal being to make the audience perceive the sounds as coming from performers on the stage, rather than from the speakers.
Refers to the resistance of a circuit or device to alternating current, which can be mathematically described as the ratio of voltage to current. Differences in impedance between devices in the studio can affect how they work together. Impedance is abbreviated by the letter Z, and measured in ohms (W).
An audio mixing console that is designed and configured so each channel strip can be used for both recording and monitoring functions during multitrack recording. This configuration is in contrast to split mixing consoles, which requires separate channels on the board for recording and monitoring functions.
The desirable situation in which two or more devices (and their respective audio signals) are on the same side of the polarity spectrum, producing waveforms that do not conflict or cancel each other out.
A jack on a MIDI device or computer that will accept an incoming data signal.
A characteristic of electrical conductors in which electrical charge (voltage) is produced or stored magnetically due to the natural resistance to change in the electrical current. Inductance is an electromagnetic principle that can either assist in audio applications (as in loudspeakers) or cause resistance (as in using speaker wire whose gauge is too low for the application).
A device (usually a coil of wire) that converts electrical energy into stored magnetic energy as electrical current passes through it. Commonly found in a variety of audio applications such as guitar pickups and loudspeakers.
A loudspeaker mount or enclosure designed so that sound waves coming from the front theoretically do not reach the back, preventing the sound waves from cancelling each other out. The term “infinite” comes from the idea that mounting the speaker on a wall with no end points would not allow sound waves to migrate behind it. Of course, this is physically impossible, so infinite baffles are designed to replicate this as much as possible. Examples of infinite baffles are mounting the speaker on a wall of an enclosed room, or building it inside a sealed cabinet large enough to prevent rear sounds from affecting the cone from the back.
The jack or physical location where a device receives a signal. Also refers to the incoming signal itself.