A lucency just means a dark area on the x-ray/CT as opposed to an opacity (which is a white area). I'm not sure what type of CT scan you got (i.e. with or without contrast injection), but don't jump to conclusions about it being cancer..... lucency just means a dark area on the x-ray/CT as opposed to an opacity (which is a white area). I'm not sure what type of CT scan you got (i.e. with or without contrast injection), but don't jump to conclusions about it being cancer.....
The operational details of amplifiers are buried in the field of electronics, but for audio purposes it is usually safe to say that current commercial audio amplifiers are so good that a normally operating amplifier is seldom the limitation on the fidelity of a sound reproduction system.
Sound will travel from one focus to the other, no matter where it strikes the wall. A whispering gallery is designed as an ellipse. If your friend stands at one focus and you stand at the other, his whisper will be heard clearly by you. No one in the rest of the room will hear anything. Reflection is responsible for many interesting phenomena. Echoes are the sound of your own voice reflecting back to your ears. The sound you hear ringing in an auditorium after the band has stopped playing is caused by reflection off the walls and other objects. A sound wave will continue to bounce around a room, or reverberate, until it has lost all its energy. A wave has some of its energy absorbed by the objects it hits.