The distinction between 'hearing' and 'listening' marks two modes of aural sense: one passive, the other actively attentive. Yet movement between them—deliberate or inadvertent—reveals liminal states that are neither fully hearing nor listening, a sense of the sonorous that exceeds the reach of these singular terms. Such thresholds have preoccupied late-twentieth- and twenty-first-century New Music composers and philosophers. This Element brings their work into dialogue to explore how these aural liminalities might be conceived. Central to the study is a close reading of the implicit liminalities in Jean-Luc Nancy's Listening (2007), which provides a framework for engaging works by Gérard Grisey, Luigi Nono, Pauline Oliveros, Morton Feldman, Bryn Harrison, and the Wandelweiser collective. By examining listening philosophies alongside musical parameters, the book amalgamates the fringes of language and sense—it is through the resulting dissonances that aural liminalities might be articulated.