The effect of speaker adaptation in human recognition of speech in noise was investigated. A set of 15 vowels, in a /t/-vowel-/t/ context, was recorded for 5 male, 5 female, and 5 child speakers. Vowels were presented in a range of signal-to-noise ratios. Recognition scores were determined in three distinct conditions. In the first condition the material was presented per speaker. In the second, the speech items from speakers within one category (male, female, or child) were mixed. In the third, the items from all speakers were mixed. The three conditions were presented to groups of listeners in random order. The largest difference in threshold, found between the first and third condition, was only 2 dB.>

Three experiments were carried out to assess the potential effectiveness of videotelephony as an adjunctive aid to speech reception by the hard of hearing. The experimental procedure consisted of audio-only and audio-visual presentation of standard prerecorded sentences to hard-of-hearing subjects who subsequently had to repeat as many words as possible. The percentage of correctly reported syllables was taken as the speech reception score. Several independent variables related to picture quality parameters. The temporal resolution (frame rate) and the spatial resolution of the video image were the most important of these. The spatial resolutions were QCIF (180*144 pixels) and 1CIF (360*288 pixels), and for both these resolutions the image was processed through a 64-kb/s codec.>