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.
In audio signal processing and acoustics, echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is proportional to the distance of the reflecting surface from the source and the listener. Typical examples are the echo produced by the bottom of a well, by a building, or by the walls of an enclosed room and an empty room. A true echo is a single reflection of the sound source.