Final answer:
An increase of 30 dB in sound intensity level would result in a significantly louder environment, likely reaching levels comparable to a jet takeoff which may be a concern for residents. The mayor's plan could mean downtown sound levels reaching 100 dB, which is 1,000 times more intense than the current level.
Step-by-step explanation:
The subject of concern here is that a proposed train service may increase the sound intensity level in a community's downtown area. Currently, the community experiences a sound level of 70 dB, which is considered to be reasonably loud—similar to the noise level of a passenger car driving by. The mayor is suggesting that the sound intensity level will increase by 30 dB due to the new train service.
An increase of 30 dB represents a sound intensity that is 1,000 times greater than the initial sound intensity level. Given that a 100 dB sound is akin to a jet plane taking off, an increase to 100 dB (70 dB + 30 dB) in the downtown area could be a significant cause for concern. For context, a 10 dB sound is extremely quiet, such as running fingers through hair, and 50 dB is the sound level inside a quiet home without any background noise such as television or radio.