BNO Acoustics HD-70: Throat

The small opening in a horn or in a driver through which the sound pressure wave passes from the driver to the horn.

BNO Acoustics BP-40: Sustain
1) A holding out of the sounding of a pitch by an instrument.
2) The level that a sound will continue to play at when a synthesizer key is held down.

Filter
1) A device that removes signals with frequencies above or below a certain point called the cut-off frequency.
2) An equalizer section, used in this sense because filters are used with other components to give an equalizer its frequency response characteristics.
3) The action of removing signals of some frequencies and leaving the rest.
4) A mechanical device to smooth out speed variations in tape machines called a Scrape Flutter Filter- more usually called a Scrape Flutter Idler

Amplifier (Power amp, Head)
It's the part of the sound system that actually magnifies or "amplifies" the sound. In other words, it makes stuff louder.

Engineer
1) A technician in charge of a recording session; Also called Recording Engineer.
2) A person with an engineering degree.
3) A person with sufficient experience in the field to be equivalent to the education one would receive earning an engineering degree.

Voltage
The electrical force pushing electrons to obtain electrical current.

BNO Acoustics GT-60: Solo Switch
A switch that activates the solo function (allowing just selected channels to be heard or to reach the output).