Each text has a companion set of cassette tapes. Each set of tapes is available and may be copied by an educational institution for classroom use but not for resale.
Tedious, dry, and often confusing this text was not my favorite for learning a language and the department at the school I'm studying Japanese at actually plans to replace this with a different textbook all together next year. I'll be keeping it and am moving on to volume II today but definitely would not recommend over a Genki textbook.