Use of Shadowing in Speech Quality Evaluation
Linda Pierce, Herman R. Silbiger · The Journal of the Acoustical Society of America · 1972
The process of listening to speech over earphones, and simultaneously repeating it is called “shadowing.” The use of shadowing as a possible method for evaluating speech transmission quality was investigated. Three methods were used for degrading speech quality: additive noise, speech correlated noise, and peak clipping. All speech was presented over earphones. Subjects practiced the shadowing test to an 85% corrcet criterion on undegraded speech, with a word presentation rate of 1.31 words/sec. A male and a female speaker were used. With all three degradations, shadowing accuracy was monotonically increasing with decreasing degradation. For a given signal-to-noise ratio, performance was better while listening to speech correlated noise than while listening to additive noise. Shadowing was found to be more sensitive to low levels of peak clipping than most types of intelligibility tests.