The purpose of this study is to determine if significant audio-metric characteristics exist in individuals having cochlear lesions who trace a Bekesy pattern characteristic of individuals with normal hearing or conductive losses.

Masking Level Difference (MLD) tests are an established component of auditory processing test batteries; however, normative data for these tests vary according to procedure. In this study, forty normal, native-English speaking adults between the ages of 18 and 26 were tested for MLD via a newly developed computer software program using both an adaptive procedure (MLDA) and a Bekesy procedure (MLDB). The results from the two procedures were analyzed for sex differences and compared with each other. For both the MLDA and MLDB, the results showed statistically significant sex differences in the masked thresholds used to obtain the MLD (NoSo and NoSπ), but no significant difference in the calculated MLD value (NoSo - NoSπ). These results suggest that since the MLD was similar for both sexes, the normative data need not be reported separately by sex. The results also showed statistically significant differences between procedures, with the MLDA procedure producing higher MLDs than the MLDB procedure. The MLDA procedure lent itself to a d´ analysis, which could not be determined using MLDB due to the nature of a Bekesy assessment. For MLDA, d´ = 1.4, test sensitivity = 96.4%, and test specificity = 60.3%. The results of this study indicate that MLDA is a better testing procedure due to MLDA's higher MLD average and the statistical data available (d´, and measures of sensitivity and specificity) when using the MLDA procedure.

Main aim of this thesis is to create an application for measuring threshold in quiet and masking curves in C++ language. First chapter describes basic teory of perceiving sound and phenomenon of masking. Second chapter focuses on description of different hearing measurement methods. Third chapter describes, how the classes and functions for frequency changing oscilator and evaluation were created and how the graph display function works. Next chapter describes, how to use the application properly and how to do the basic calibration, so the data will be displayed correctly. Last chapter shows the correct function, measured thresholds in quiet and masking curves for two subjects.

Masking Level Difference (MLD) tests are an established component of auditory processing test batteries; however, normative data for these tests vary according to procedure. In this study, forty normal, native-English speaking adults between the ages of 18 and 26 were tested for MLD via a newly developed computer software program using both an adaptive procedure (MLDA) and a Bekesy procedure (MLDB). The results from the two procedures were analyzed for sex differences and compared with each other. For both the MLDA and MLDB, the results showed statistically significant sex differences in the masked thresholds used to obtain the MLD (NoSo and NoSπ), but no significant difference in the calculated MLD value (NoSo - NoSπ). These results suggest that since the MLD was similar for both sexes, the normative data need not be reported separately by sex. The results also showed statistically significant differences between procedures, with the MLDA procedure producing higher MLDs than the MLDB procedure. The MLDA procedure lent itself to a d´ analysis, which could not be determined using MLDB due to the nature of a Bekesy assessment. For MLDA, d´ = 1.4, test sensitivity = 96.4%, and test specificity = 60.3%. The results of this study indicate that MLDA is a better testing procedure due to MLDA’s higher MLD average and the statistical data available (d´, and measures of sensitivity and specificity) when using the MLDA procedure.