What is "phonaesthetics"

Phonaesthetics (from the phōnē, "voice-sound"; and aisthētikē, "aesthetics") is the study of the inherent pleasantness (euphony) or unpleasantness (cacophony) of the sound of certain words, phrases, and sentences.

The closely related but different concept of phonaesthesia should be distinguished from this meaning. Phonaesthesia does not refer directly to aesthetic attributes of sound, but to phonetic elements that are inherently associated with a semantic meaning.