Highlight language that appeals to your senses. But, alas! this kind heart had but a short time to remain such. The fatal poison of irresponsible power was already in her hands, and gradually commenced its infernal work. That cheerful eye, under the influence of slavery, soon became red with rage; that voice made all of sweet accord, changed to one of harsh and horrid discord; and that angelic face gave place to that of a demon.

—Narrative of the Life of Frederick Douglass,
Frederick Douglass

The phrase "that voice made all of sweet accord, changed to one of harsh and horrid discord" appeals to which sense?

sight
touch
smell
hearing