Recent work by Martin, Osberger, and Pickett shows that for both normal and hearing-impaired subjects, F1 causes considerable masking of F2 transitions at the higher intensity levels typically necessary for exceeding the speech reception threshold (SRT) in the hearing impaired. Accordingly, we have processed normal speech to alter the relative intensities of F1 and F2 over a considerable range and presented this processed speech to adventitously sensorineural hearing-impaired subjects. We have also presented normal (unweighted) speech to the same listeners at the same true rms level as a comparison. The weighting is accomplished by using a high pass filter with variable attenuation slopes. Intensities of weighted and unweighted speech were 20, 30, 40 dB above the SRT for normal speech. Results show that weighting usually increases discrimination for a given level, even though subjects received no feedback and so no learning was designed to take place. Despite the fact that subjects complain that the treated speech is -squeaky,- etc., they do find it immediately more intelligible by at least 20% using Harvard PB words as test materials.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.