Various sound-recording technologies are presented that use different mediums and different encoding methods for the recorded signal. Analog and digital are two broad categories used for encoding. Sound signals can be recorded using a physical change to a material, as is used for vinyl records and some CDs and DVDs. Signals can also be recorded using magnetic materials and their interaction with electromagnets. Optically encoded signals involve a change in the reflection or transmission of light from a material, including the analog signals used in older movie films and digitally recorded signals for newer recordings. Two examples of digital recording encoding are 1-bit and base-2 binary. Nyquist folding, used when sampling is too slow, is introduced.

Chapter 6 begins with an extended discussion of intentionality and pattern, and applies it to distinguishing the concepts of signal, cue, and incidental behavior.These concepts are then applied to a more precise definition of communication.There follows a detailed discussion of signals, signaling systems, and language. Then Chapter 6 covers the role of signals in conversation and in relationship.Finally, the chapter takes up the topic of ad hoc signals, and the question, whether communicative signals are analog or digital.