Pitch

The perceived highness or lowness of a sound, determined primarily by its fundamental frequency (measured in Hertz). Pitch is one of the primary dimensions along which music and speech are organized, underpinning melody, harmony, and prosody. In accessibility work, pitch is relevant to captioning and sound visualization for Deaf and Hard-of-Hearing users (e.g., mapping pitch contour to on-screen vertical position or baseline shift), to speech-recognition fairness across voices of different pitch ranges, and to assistive listening technologies that may compress, shift, or amplify specific pitch bands.