Macmillan has acquired the book, e-book, audiobook, and audio original catalogs of its longtime distribution client, Sounds True. Based in Louisville, Colo., Sounds True was started in 1985 by Tami Simon as an audiobook publisher in the wellness and mind-body-spirit space and gradually expanded into other media, including books and e-books.

According to the Macmillan announcement, the deal includes all backlist works, forthcoming titles, and original audio content. Books and e-books will be published under St. Martin’s Essentials and carry that imprint's name while Sounds True audio content will be published by Macmillan Audio under the Macmillan Audio name.

Simon will remain with Sounds True and focus on the company’s direct-to-consumer platform, which includes online learning, events, and digital media. “After forty years, it feels like a growth-filled evolution for our publishing program to expand further with such a trusted and mission-aligned partner,” Simon said in a statement.

According to Sounds True’s website, the company has about 3,000 titles, but a Macmillan spokesperson couldn’t confirm the number of works it acquired.

The purchase marks a rare acquisition for Macmillan, which has focused on starting new imprints and other internal initiatives to grow rather than going the acquisition route. “This acquisition represents our deepening investment in content that helps people live with greater intention, clarity, and purpose,” said Macmillan CEO Jon Yaged in a statement.

As part of St. Martin’s Essentials, Sounds True’s books and e-books will be overseen by Jennifer Enderlin, president and publisher of the St. Martin’s Publishing Group. Mary Beth Roche, president and publisher of Macmillan Audio, will oversee the integration of Sounds True audio catalog.

Among the Sounds True authors joining St. Martin’s Essentials and Macmillan Audio are Jon Kabat-Zinn, Pema Chödrön, Richard C. Schwartz, Caroline Myss, David Deida, Tara Brach, Wim Hof, Terri Cole, and Jack Kornfield.