Intelligibility of voice transmission through a satellite relay system
Paul Milner, J. Golab · The Journal of the Acoustical Society of America · 1975
An extensive series of measurements of speech intelligibility of voice modems designed for a satellite relay link to air and sea-going craft has been underway since 1973. Measurement parameters for these tests are the system functions associated with ATS-6 satellite L-band and C-band transmission. These include comparative evaluations of intelligibility versus C/N0, angle of elevation, antenna systems, range, and sea-state. For these tests, a number of modifications and adaptations of standard intelligibility testing procedures were developed. These include using a large number of scramblings of the PB-50 word lists (ANSI S3.2-1960) recorded by four professional talkers, two male and two female, in an anechoic room. Because of time considerations in conducting the flight tests, the lists were recorded at a reading rate of 2.5 sec with no carrier phrase Experiments showed that highly trained listeners [P. Milner, “Advantages of Experienced Listeners in Intelligibility Testing,” IEEE Trans. Audio Electroacoust. AU-21, 161–165] have no difficulty performing the open response task at this rate and that correlation between this method and the usual method is high. [This work performed under U. S. Dept. of Transportation Contract No. DOT-TSC-604.]