Final answer:
120 dB is 10 to the power of 12 times more intense than the threshold sound level, since every 10 dB increase equates to a tenfold increase in sound intensity.
Step-by-step explanation:
To determine how many times 120 dB is greater than the threshold sound level, we utilize the logarithmic scale of sound intensity measured in decibels (dB). The threshold of hearing is defined at 0 dB, meaning this is the point at which sound is perceptible to the average human ear.
Because an increase of 10 dB represents a sound that is 10 times more intense, a sound that is 120 dB is 12 factors of 10 greater in intensity than the threshold level. Therefore, 120 dB is 1012 times more intense than the threshold level of 0 dB. Each factor of 10 in intensity corresponds to 10 dB. For example, a 90 dB sound compared with a 60 dB sound is 30 dB greater, or three factors of 10 (that is, 10³ times) as intense. Therefore, to find how many times 120 dB is greater than the threshold sound level, we need to find the difference in dB between the two levels and convert it into a factor.
120 dB - threshold sound level = 120 dB - 0 dB = 120 dB
Since 120 dB is the maximum sound level, it is not possible to compare it with any higher sound level using the factor of 10 in intensity.