The effects of high pass filtered speech on speech discrimination

This study was designed to determine the intelligibility of speech at two intensity levels using two different conditions (broad band and high pass filtered speech) and to determine the vowels and consonants most affected by the conditions imposed. The ten subjects were all stimulated with 50 words of the CID W-22 series at two levels of intensity (30 db SL and 15 dB SL) each in the filtered and broad-band (unfiltered) conditions. The results tended to indicate that the type of condition (filtered or unfiltered) did not affect the speech comprehension until the intensity of the filtered signal approached 15 dB SL. It was also determined that consonants and vowels identification were only slightly affected by filtering if the intensity of the signal is above 15 dB SL.