Final answer:
A sound that is 1,000,000 times more intense than the softest sound we can hear has a loudness level of 60 dB, comparable to the loudness of a normal conversation.
Step-by-step explanation:
If a sound is 1,000,000 times more intense than the softest sound a human ear can detect (0 dB being the threshold of hearing), we can calculate its loudness in decibels using the logarithmic scale of sound intensity.
A factor of ten increase in intensity corresponds to an increase of 10 decibels (dB). Therefore, since the sound in question is 1,000,000 times (or 106 times) more intense, we calculate the increase in loudness as being 6 factors of 10, which leads to an increase of 60 dB.
Given that the threshold of hearing is 0 dB, adding this 60 dB increase, we find that the loudness level of the sound is 60 dB. This is a similar loudness to that of a normal conversation. Note that while loudness gives a general idea of the intensity, it does not account for factors like frequency and timbre that also affect how we perceive sound.