Subjective Effects of Noise and Loss in Telephone Transmission

This paper describes an experiment that was performed to study the subjective effects of noise and loss on actual telephone calls made within the Murray Hill location of Bell Telephone Laboratories. The effects of noise and loss on talker volume as well as on transmission quality ratings are discussed. A joint transmission grade of service is obtained, which shows, for various distributions of noise and loss in the circuit, the expected percentage of customers rating the circuit quality as "good or better," and "poor or worse."