Final answer:
The graphic representation of sound pressure level or voltage level is called a waveform, which displays the variations in pressure or voltage over time. The sound intensity level in decibels is calculated using the logarithm of the sound intensity ratio to a reference intensity. An increase of 40.0 dB results in the amplitude of the sound wave increasing by a factor of 10.
Step-by-step explanation:
The graphic representation of a sound pressure level or voltage level is called a waveform. A waveform graphically displays the variation of sound pressure or voltage against time. It shows the oscillations of pressure due to a sound wave, where the amplitude represents how compressions and rarefactions of the sound wave vary over time.
Amplitude, on a waveform display, is the dimension from the center line (zero pressure/voltage level) to the peak (maximum pressure/voltage) or to the trough (minimum pressure/voltage).
To calculate the sound intensity level in decibels (dB), one needs to use the logarithm of the ratio of the particular sound intensity to a reference sound intensity, typically the lowest intensity sound a person can hear. The formula is B = 10 * log(I/I0), where B is the sound intensity level in dB, I is the sound intensity, and I0 is the reference sound intensity.
When the sound intensity level increases by 40.0 dB, the amplitude of the sound wave, in terms of pressure, correspondingly increases. Given that the dB scale is logarithmic, a 40 dB increase represents a 100-fold increase in intensity. Because intensity is proportional to the square of the amplitude (pressure), the amplitude would increase by a factor of 10.