New Each package has two CDs with high-quality recordings, and a 32-page booklet, both designed as companions to our popular field guides. Casual birders will enjoy learning the sounds of the birds at their feeders by finding just the sound they want or simply following along with the book, as the CD sounds are in the same order. Each bird has its own track with the track icon at the bottom of the field guide page to quickly locate the sound. Experienced birders will love the high-quality digital sounds, and the length and variety of all the calls. Because the sounds are for just the birds in each state, they include regional dialects (a cardinal in Minnesota does not sound the same as one in Florida). The best quality audio you'll find with a unique, made-to-fit design for the field guides. While designed as companions, the CDs can be enjoyed without the use of the book.