John works as a ground staff at a military airport . While monitoring the test flight of a jet plane , he accidentally stand too close the engine and the loud noise renders him deaf. This permanent damage to his hearing is possible when the sound level is

Options

A. 50 dB or more
B. 100 dB or less
C. 150 dB or more
D. 10 dB or less

Answer

To determine the sound level that can cause permanent damage to hearing, we need to analyze the information provided in the question and the context of noise pollution.

### Step-by-Step Solution:

1. **Understanding Noise Levels**:
- Sound is measured in decibels (dB). Different levels of sound can have varying effects on hearing.
- Normal conversation is around 60 dB, while sounds above 85 dB can be harmful with prolonged exposure.

2. **Identifying Dangerous Sound Levels**:
- Research indicates that sounds above 120 dB can cause immediate harm to hearing.
- Sounds at 150 dB or more are extremely loud and can lead to permanent hearing loss almost instantly.

3. **Context of the Situation**:
- John was monitoring a test flight of a jet plane. Jet engines produce very high noise levels, often exceeding 130 dB during takeoff.
- Standing too close to such an engine can expose an individual to sound levels that are potentially damaging.

4. **Conclusion**:
- Based on the information, the sound level that can cause permanent damage to hearing is **150 dB or more**.

### Final Answer:
The permanent damage to John's hearing is possible when the sound level is **150 dB or more**.

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