What phenomenon occurs when sound energy matches a system's natural frequency?

• A. Absorption
• B. Refraction
• C. Resonance
• D. Reflection

Answer: (C)

Resonance occurs when sound energy aligns with a system's natural frequency, leading to an amplification of sound. This phenomenon can be observed in various contexts, such as musical instruments, where specific frequencies produce stronger vibrations and louder sounds due to the matching of the sound waves with the instrument's resonant frequency.

In essence, when the frequency of an external sound wave corresponds with the natural frequency of a system, the system efficiently absorbs the sound energy and vibrates more vigorously. This is the principle behind instruments like tuning forks and guitars, where certain pitches resonate more effectively, resulting in a richer, fuller sound.

The other choices represent different acoustic phenomena: absorption refers to the loss of sound energy as it is taken in by materials, refraction involves the bending of sound waves as they move through different mediums, and reflection is the bouncing back of sound waves when they hit a barrier. Each of these plays a role in sound behavior, but they do not involve the specific matching of frequency that characterizes resonance.