Sounds as loud as _____ are comfortable to the human ear.

Options

A. 60-65 dB
B. 70 - 80 dB
C. 20 - 25 dB
D. 80 - 100 dB

Answer

To answer the question, "Sounds as loud as _____ are comfortable to the human ear," we need to determine the range of sound levels that are considered comfortable for human hearing.

### Step-by-Step Solution:

1. **Understanding Decibels**:
- The loudness of sound is measured in decibels (dB). This is the unit we use to quantify sound intensity.

2. **Identifying Comfortable Sound Levels**:
- Research indicates that sounds above 80 dB can be uncomfortable or even painful for the human ear. Sounds at this level can lead to hearing damage and other health issues.

3. **Determining the Maximum Comfortable Level**:
- Since sounds louder than 80 dB are uncomfortable, we need to find the range of sounds that are less than this level.

4. **Evaluating Options**:
- We need to look at the options provided for the sound levels that are comfortable.
- Common comfortable sound levels range from 60 dB to 70 dB. Sounds in this range are generally considered pleasant and non-intrusive.

5. **Conclusion**:
- Therefore, sounds as loud as **70 dB** are comfortable to the human ear.

### Final Answer:
Sounds as loud as **70 dB** are comfortable to the human ear.

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