R. Murray Schafer, a Canadian composer and writer who brought the concept of the “soundscape” to widespread recognition and pioneered the field of acoustic ecology — the relationship between sound, people and the environment — died on Aug. 14 at his home near Peterborough, Ontario. He was 88.

The cause was dementia, his wife and collaborator, the mezzo-soprano Eleanor James, said.

Mr. Schafer was already an inventive avant-garde composer when he began researching the relationship between sound and the environment in the late 1960s. He had joined a noise abatement society but disagreed with its treatment of noise as a negative phenomenon.

“The sounds of the environment were changing rapidly, and it seemed that no one was documenting the changes,” he recalled in his 2012 memoir, “My Life on Earth and Elsewhere.” “Where were the museums for disappearing sounds? What was the effect of new sounds on human behavior and health?”

With funding from UNESCO and the Donner Canadian Foundation, Mr. Schafer formed the World Soundscape Project at Simon Fraser University in British Columbia. His team of researchers compiled information about noise bylaws, conducted interviews about sounds of the past and tallied car horns honking at street intersections around the world.

“It’s quite the task for people to understand that listening can be a very active and inspiring activity,” the composer Hildegard Westerkamp, who was a researcher for the project, said in an interview. “A socially conscious ear, and a culturally conscious ear, and a politically conscious ear — that’s all the legacy that he has given to us.”

In 1977, Mr. Schafer published “The Tuning of the World,” a treatise on acoustic ecology, which has influenced generations of scholars and musicians. Drawing on poetry, biology and myth, the book provides a history of the world through its soundscapes while offering instructions in “ear cleaning” and sound walks to reconnect readers with their sonic environments.

His immersion in environmental listening changed his compositional interests. In 1979, he composed “Music for Wilderness Lake,” in which 12 trombonists played around the shore of a small lake at dusk and dawn; floating on a raft, Mr. Schafer conducted them with colored flags.

Such experiments formed the basis for “Patria,” a cycle of 12 theatrical works composed over 40 years that mingles world mythologies. In one installment, audience “initiates” chant in ancient Egyptian as part of an overnight performance; another of the works unfolds as a carnival.

For the cycle’s epilogue, a “co-opera,” several dozen participants have for more than 30 years made a weeklong pilgrimage each August to Ontario’s Haliburton Forest and divide into clans to create collaborative theatrical rituals.

Raymond Murray Schafer was born July 18, 1933, in the Lake Huron city of Sarnia, Ontario, to Harold Schafer, an accountant for an oil company, and Belle Anderson Rose. He was born blind in one eye and, following a pair of operations at age 8, was given a glass eye, for which he was bullied in school in Toronto. He took piano lessons starting at 6 but was intent on being a painter.

Discouraged by others from pursuing a career in art because of his eye condition and failing out of high school, Mr. Schafer ended up at the University of Toronto’s Royal Conservatory of Music, where he studied with the composer John Weinzweig and attended classes taught by the media theorist Marshall McLuhan.

Already a keen intellectual, he preferred reading Rousseau to practicing piano; he angered one choir director by perusing art books during rehearsal. After several such incidents, he was thrown out of the school (though it later awarded him an honorary doctorate).

Intent on studying composition in Vienna, Mr. Schafer worked as a deckhand on an oil tanker to raise travel funds. He roamed Europe — interviewing British composers for the Canadian Broadcasting Corporation, learning medieval German, attending a folk music conference in Romania — without a clear plan for his musical future.

In Italy, Mr. Schafer convinced Ezra Pound to allow him to revive the poet’s little-known opera, “Le Testament de Villon,” which became a major BBC broadcast in 1962. (Pound gave him an envelope containing his final series of “Cantos” and asked him to deliver it to T.S. Eliot in London.)

On his return to Toronto, Mr. Schafer in 1962 co-founded the innovative concert series Ten Centuries, which presented new and rarely heard music.

As his career picked up, he answered requests for new works with irreverence, composing “Son of Heldenleben,” a parodic riff on the tone poem by Richard Strauss, and “No Longer Than Ten (10) Minutes,” in which an orchestra tunes up, a conductor walks on and offstage, and the players crescendo each time the audience tries to applaud. His 1966 “Requiems for the Party-Girl,” written for the mezzo-soprano Phyllis Mailing, is a darkly virtuosic monodrama in which a woman sings of her impending suicide.

Mr. Schafer married Ms. Mailing in 1960, and they divorced in 1971. His second marriage, to Jean Reed, from 1975 to about 1999, also ended in divorce. He married Ms. James in 2011 after a long partnership. Along with her, he is survived by his brother, Paul.

Mr. Schafer began his research on soundscapes after joining the faculty at Simon Fraser University in 1965. He also invented a radical approach to teaching, calling it “creative music education.” In a series of influential booklets, he provided exercises to encourage children’s creativity, asking them to “bring an interesting sound to school” or hum along with a tune that they had heard on a street corner.

Alongside the mythic theater of “Patria,” Mr. Schafer composed more conventional scores, among them 13 string quartets and “Letters from Mignon,” a neo-Romantic song setting of love letters written to him by Ms. James. His genre-spanning oratorio “Apocalypsis” was first performed with a cast of more than 500 in 1980; it received a triumphant, career-capping revival at the Luminato Festival in Toronto in 2015.

In a 2009 short film directed by David New, Mr. Schafer offers philosophical musings on listening amid the snowy soundscape outside his home, a remote farmhouse in the Indian River area in southern Ontario.

“The world is a huge musical composition that’s going on all the time, without a beginning and presumably without an ending,” he said.

“We are the composers of this huge, miraculous composition that’s going on around us. We can improve it, or we can destroy it. We can add more noises, or we can add more beautiful sounds. It’s all up to us.”