Final answer:
The townspeople should be concerned about the significant increase in the sound intensity level from 70 dB to 100 dB due to the introduction of train service, which is perceived as roughly eight times louder. Noise abatement strategies will be crucial to mitigate the impact of this change. Noise-canceling headphones reduce noise through destructive interference, unlike standard headphones which rely on physical barriers.
Step-by-step explanation:
A community is concerned about the potential increase in sound intensity level due to the introduction of a train service downtown. With the current sound level at 70 dB, an increase of 30 dB (as mentioned by the mayor) will lead to a new sound level of 100 dB, which is a significant increase in terms of perceived loudness.
Generally, every 10 dB increase is perceived as a doubling of loudness, so a 30 dB increase is perceived roughly eight times louder. This can have various negative effects on the well-being of the townspeople and could lead to noise pollution concerns.
Hence, the townspeople should indeed be concerned unless effective noise abatement measures are put into place to mitigate the impact. Noise-canceling headphones differ from standard headphones in that they use destructive interference to actively reduce ambient noise, while standard headphones rely solely on passive noise blocking through the physical barrier created by the headphones themselves.
In a room, destructive interference can cause sounds to be softer in some areas where the interference is destructive, while constructive interference can amplify sounds in other areas.