Re: "Greek compressor" - do you know the term?
Heard the term for the first time today. Are you familiar with it?
The term refers to vocal technique.
Greek compressor, or vocal compression as it is also named, is a manner of using cartilages in your larinx (that's where the vocal cords are) to "compress" the vocal chords, giving your singing voice a specific tone and texture. The cartilages herewith are called arytenoids, and have the same effect to the chords as the keys on a string instrument have on its strings or, particularly, the whammy bar (tremolo bar) has on a guitar. The arytenoids can be tensioned by larinx muscles and thus modify the oscillating frequency of the vocal chords and thus, the tone and pitch of the voice. This technique is feared by many beginner singers, as they mistake it for "tensioning" vocal chords.
However, if correctly learned (and taught), it can not only produce a good singing voice with surprising effects and intensity, yet also a healthy use of the vocal chords, unlike tensioning which can cause overburden of vocal chords with unwanted and even pathological effects.
There are also some interesting demonstrations on You Tube as to the use of VOICE (or GRECIAN) COMPRESSOR.
Shortly, this is no piece of hardware, but a most particular VOCAL TECHNIQUE used by singers.