Portland State University. Department of Speech
Date of Award
Master of Science (M.S.) in Speech
1 online resource (58 p.)
Previous investigations of masking have established that the action of the masking tone spreads upward in frequency, creating significantly more masking (threshold shift) above the masker frequency than below. It was the purpose of this study to investigate the masking pattern produced by high frequency pure tones, heretofore uninvestigated.
Masking patterns were obtained for nine normal hearing young adults utilizing the method of adjustment. The masking produced by an 11000 Hz pure tone of 40 dB sensation level was measured at three frequencies above and three frequencies below the masker frequency. Analysis of the data revealed a downward spread of masking. Pure tone stimuli below the 11000 Hz masker showed significantly more threshold shift than those above the masker frequency. On the basis of the data collected in this investigation, it must be concluded that the upward-spread-of-masking phenomenon is not applicable at certain high frequencies.
A method for obtaining high frequency thresholds is discussed and the results compared to recent normative studies pertaining to the extra high frequencies.
Widen, Judith Eide, "Masking patterns of high frequency pure tones" (1974). Dissertations and Theses. Paper 2431.