The greater the amplitude, the higher the intensity and the louder the sound.
Intensity of a wave is proportional to the square of its amlitude so it should decrese when the amplitude is decreased.
the amlitude of the input signal 10 volt peak to peak was set at 10 khz
Amplitude shift keying changes the height/power of the transmitted signal without altering the frequency. Frequency shift keying changes the frequency of the transmission without altering the height/power of the transmitted signal. Morse code is an example of amplitude keying where the amplitude is 0 or 100%. RTTY teleprinter uses FSK with two frequencies and the codes that represent text characters are sent with patterns of the two frequencies.