Difficulty: Easy
Correct Answer: 95
Explanation:
Introduction / Context:
Urban noise exposure often occurs during commuting. Recognizing typical levels helps in assessing daily noise dose relative to occupational or environmental guidelines.
Given Data / Assumptions:
Concept / Approach:
Typical interior levels in buses and subway cars can range from roughly 85 to 100 dB(A) depending on vehicle condition, speed, and crowding. A mid-high value around 95 dB is often cited for noisier conditions and matches the upper typical range of such environments.
Step-by-Step Solution:
Verification / Alternative check:
Field measurements reported by urban acoustic surveys frequently find 90+ dB inside older subway cars or crowded buses during peak conditions.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing indoor public spaces (often 60–70 dB) with amplified transit environments that include mechanical and structural noise sources.
Final Answer:
95
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