What is diffraction in the context of sound waves?

In the context of sound waves, diffraction refers to the phenomenon that occurs when sound waves encounter an opening or obstacles. The waves then bend and spread out as they pass through the opening or around barriers. This bending is most noticeable when the size of the opening or barrier is comparable to the wavelength of the sound.

Diffraction allows sound to reach areas that would otherwise be shadowed or obstructed. For instance, this is why you can still hear a conversation from around a corner or why sound can travel into a room through an open door, even if the source is not in direct line of sight. Understanding diffraction is crucial for hearing instrument specialists, as it greatly affects how sound is perceived in various environments and can influence the fitting and adjustment of hearing aids to ensure optimal sound quality for users.

The other options pertain to different acoustic concepts. While a change in frequency relates to the Doppler effect or pitch alterations, amplitude changes involve loudness variations, and absorption refers to sound energy being taken up by surfaces rather than reflected.