Selected procedures and related norms for most comfortable loudness measures

The purpose of this study was to indicate norms for most comfortable loudness levels (MCLs) and to investigate the relationships among MCL and related measures. In addition MCL values for males and MCL values for females were separated to see if any differences existed between sexes.A pure tone average (PTA) and a spondee threshold (ST) were obtained for each of 54 subjects (23 males, 31 females) to assure normal hearing. The following measures were then obtained on all subjects: 1.) The MCL was obtained using a bracketing method. 2.) A Bekesy audiometer was used to determine MCL using both a 2.5 dB/second and a 5 dB/second attenuation rate. 3.) The lower limit of the most comfortable loudness range (LLMCR) was determined using a nonBekesy procedure. 4.) The upper limit of the most comfortable loudness range (MCR). Again, both 2.5 dB/second and 5 dB/second attenuation rates were used. The Bekesy MCR tracings also provided the ULMCR and the LLMCR values for Bekesy obtained MCRs. Four analyses of variance (ANOVA) were computed for various MCL and MCR measures to investigate the relationships among these measures. It was concluded that no significant differences occurred between males and females in all MCL and related measures.Averages were presented for each individual MCL procedure which ranged from 51.29 dB to 56.77 dB HL. Average MCRs (actual ranges) were 30.54 to 42.78 dB. Some significant differences were found among specific procedures which are discussed in the text, however, these differences may not be significant from a clinical standpoint. In general, non-Bekesy procedures were recommended for use clinically because they produced the least variability in subjects and they require the least amount of time in administration.Thesis (M.A.