Brooks RM 909 reviews Insert

1) A punch in of the all of the tracks being recorded in a recording session.
2) On Solid State Logic consoles, placing an outboard piece of gear in the channel by patching and activating a switch.

Expansion
The opposite of compression; for example, an expander may allow the signal to increase 2 dB every time the signal input increased by 1 dB.

Brooks RM 909 Ambient Field
A term with the same meaning as the term Reverberant Field (the area away from the sound source where the reverberation is louder than the direct sound).

Generation
A term used to describe the number of times that the recorded audio signal has been copied.

Brooks Hi Fi reviews IM Distortion
An abbreviation of the term Intermodulation Distortion (Distortion caused by one signal beating with another signal and producing frequencies that are both the sum and the difference of the original frequencies present).

Ground Loop
A double grounding of a line or electronic device at two different "ground" points of differing voltage.

Feedback
1) The delayed signal sent back to the input of a delay line, used in repeat-echo effects.
2) The pickup of the signal out of a channel by its input or the howling sound that this produces.
3) In an amplifier, the phase reversed output signal sent back to its input, reducing gain but also distortion and noise.
4) This occurs when the sound coming out of the speakers goes back into the microphones, then back out the speakers, then back into the mics…and so on. This can build very quickly to a point where everyone in the room is holding their ears and screaming at you. It can also cause damage to the PA.

Comb Filter
1) The frequency response achieved by mixing a direct signal with a delayed signal of equal strength especially at short delays.
2) Loosely used to also describe effects that can be achieved with comb filtering as part of the processing.