This chapter from D.E. Broadbent's book "Perception and Communication" focuses on the experimental study of selective listening to speech, emphasizing the central processes involved in hearing rather than sensory mechanisms. The author reviews existing literature and experimental findings to highlight the importance of understanding how the brain processes multiple simultaneous stimuli. Key points include: 1. **Central vs. Sensory Effects**: Experiments show that difficulties in listening to multiple messages are not due to sensory masking but rather to central processing within the listener's brain. 2. **Information Theory and Capacity**: The performance of selective listeners seems to vary with information as defined by communication theory, rather than with the amount of stimulation. This suggests a limited capacity for the nervous system. 3. **Physical Conditions**: The physical arrangement of sound sources and the use of different sensory channels (e.g., binaural versus monaural) can significantly affect the listener's ability to process multiple messages. 4. **Message Characteristics**: The characteristics of the message, such as its content and the speaker's voice, can influence the listener's ability to focus on relevant information. Similar messages or those from different speakers are more difficult to ignore. 5. **听众的意识和行为**：Cherry's experiments show that listeners can notice changes in the content of the ignored message, even if they cannot recall specific details, indicating that some information from the rejected message is still processed. Overall, the chapter underscores the importance of understanding the central processes involved in selective listening, which have implications for both theoretical and practical aspects of communication and behavior.This chapter from D.E. Broadbent's book "Perception and Communication" focuses on the experimental study of selective listening to speech, emphasizing the central processes involved in hearing rather than sensory mechanisms. The author reviews existing literature and experimental findings to highlight the importance of understanding how the brain processes multiple simultaneous stimuli. Key points include: 1. **Central vs. Sensory Effects**: Experiments show that difficulties in listening to multiple messages are not due to sensory masking but rather to central processing within the listener's brain. 2. **Information Theory and Capacity**: The performance of selective listeners seems to vary with information as defined by communication theory, rather than with the amount of stimulation. This suggests a limited capacity for the nervous system. 3. **Physical Conditions**: The physical arrangement of sound sources and the use of different sensory channels (e.g., binaural versus monaural) can significantly affect the listener's ability to process multiple messages. 4. **Message Characteristics**: The characteristics of the message, such as its content and the speaker's voice, can influence the listener's ability to focus on relevant information. Similar messages or those from different speakers are more difficult to ignore. 5. **听众的意识和行为**：Cherry's experiments show that listeners can notice changes in the content of the ignored message, even if they cannot recall specific details, indicating that some information from the rejected message is still processed. Overall, the chapter underscores the importance of understanding the central processes involved in selective listening, which have implications for both theoretical and practical aspects of communication and behavior.