Sound Waves: Characteristics and Applications · Lesson 10 of 14
Reflection of Sound
“Sound can bounce from surfaces and obey the same reflection geometry used for light.”
• Define reflection of sound. • State the laws of reflection for sound. • Identify incident and reflected sound directions. • Explain how reflecting surface properties affect reflected sound.
Sound does not always disappear when it reaches a surface. Part of the wave can return into the original medium. This bouncing of sound is called reflection.
Reflection of Sound
The bouncing back of sound waves from an obstacle or boundary such as a solid or liquid surface.
The chapter states that sound follows the same laws of reflection as light. The incident sound and reflected sound make equal angles with the normal drawn at the point where the wave meets the reflecting surface. The incident direction, reflected direction and normal lie in the same plane.
Hard, smooth surfaces tend to produce strong reflected sound. Soft materials tend to absorb more sound, while rough surfaces scatter sound in different directions.
Angles are measured from the normal, not from the surface itself.
Quiz
Which description best matches Reflection of Sound?
Which term matches this description: The bouncing back of sound waves from an obstacle or boundary such as a solid or liquid surface.
Which statement is a key takeaway from this lesson?
Which additional statement is also a key takeaway from this lesson?
Which further statement is also a key takeaway from this lesson?
Practice Problems
- Define reflection of sound.
- State the two reflection conditions given in the chapter.
- If an incident sound ray makes an angle of 35° with the normal, what is the reflection angle?
- Why do soft curtains generally produce weaker reflected sound than a hard wall?
Key Takeaways
• Sound can reflect from suitable surfaces instead of being completely absorbed. • The angle of incidence of a sound wave equals the angle of reflection. • The incident sound, reflected sound and normal lie in the same plane. • Reflection of sound is used in several devices and acoustic applications.