That Audible Slippage invokes a poetics of active listening and environmental sound to investigate the ways in which we interact with the world, balancing perception and embodiment alongside a hypnagogic terrain of grief and mortality.Audibility is a primary theme of this collection—what can be heard, what is obstacled, and what remains unheard.Many of the poems included in the collection try to hold spaces open for the slipperiness of the heard and unheard and the not-yet heard and their associated problems: error, insufficiency, loss, incompleteness, and other affects such as fear and avoidance. “A Branch of Happen,” the opening section of award-winning poet Margaret Christakos’ collection, explores interior listening to both the self as sensation machine and the collaged external soundscape we both hear and fail to hear within the assailing violences and inequities of the news.A second suite, “Heart is a Guest Whippet Resting on a Firm Trunk,” is troubled by memories of deceased loved-ones amid the North Saskatchewan River valley and the many-layered history of amiskwaciwâskahikan (Edmonton).The fragmentary “Listening Line Not” multiplies the treatment of listening as a situated perceptual, sensory, and ethical process.A final long poem called “The Incubation” navigates ideas of being asleep and awake, altered and attuned, as well as spiritually dis/located in time and space.Poised within and beyond both established and emergent traditions of ecocriticism, contemporary feminisms, and experimental lyric, this intriguing and probing work of sound-illuminated poems welcomes readers into its overlapping worlds with grace.