Which term describes a harsh or grating sound?

The term "strident" specifically refers to a sound that is loud, harsh, and grating. It often connotes a sense of unpleasantness and can evoke a strong emotional response due to its jarring quality. Strident sounds are typically piercing or shrill, making them stand out in stark contrast to more harmonious or soft sounds. This makes "strident" the most appropriate choice for describing a harsh or grating sound.

In comparison, the other terms describe characteristics of sound that are more pleasing or gentle. "Melodious" refers to sounds that are tuneful and pleasant to hear, while "soothing" implies a calming and gentle quality. "Soft" generally indicates a low volume or gentle nature, which does not align with the concept of harshness. Thus, "strident" stands out as the clear choice for a sound that is indeed harsh or grating.