Audio-visual observation of spoken spondaic words was found to be superior to recognition via audition-only under a wide range of S/N conditions. Data from five subjects supported the notion that observers rely increasingly more on visual cues for speech information as S/N ratio is degraded. Audition-only performance was found to be less variable among subjects than was audio-visual recognition. Increased variability in audio-visual scores at poorer S/N ratios was attributed to differences in lip-reading skill among untrained subjects. Speech levels so low that recognition by audition-only approximated chance behavior were found, nevertheless, to systematically improve observers' audio-visual scores as a function of increasing S/N ratio.

Hearing-impaired persons usually perceive speech by watching the face of the talker while listening through a hearing aid. Normal-hearing persons also tend to rely on visual cues, especially when they communicate in noisy or reverberant environments. Numerous clinical and laboratory studies on the auditory-visual performance of normal-hearing and hearing-impaired children and adults demonstrate that combined auditory-visual perception is superior to perception through either audition or vision alone. This paper reviews these studies and provides a rationale for routine evaluation of auditory-visual speech perception in audiology clinics.

No abstract

The consonants /b, d, g, k, m, n, p, t/ were presented to normal-hearing, severely hearing-impaired, and profoundly deaf children through auditory, visual, and combined auditory-visual modalities. Through lipreading alone, all three groups were able to discriminate between the places of articulation (bilabial, alveolar, velar) but not within each place category. When they received acoustic information only, normal-hearing children recognized the consonants nearly perfectly, and severely hearing-impaired children distinguished accurately between voiceless plosives, voiced plosives, and nasal consonants. However, the scores of the profoundly deaf group were low, and they perceived even voicing and nasality cues unreliably. Although both the normal-hearing and the severely hearing-impaired groups achieved nearly perfect recognition scores through simultaneous auditory-visual reception, the performance of the profoundly deaf children was only slightly better than that which they demonstrated through lipreading alone.

This paper describes an audiologic test battery for hearing-impaired children which includes otoscopic examination, tympanometry, pure-tone audiometry, speech perception testing, and hearing aid evaluation. Several of the procedures and modifications to apparatus have been developed specifically for use with deaf children. Clinical data are presented from 160 hearing-impaired children (age range three-16 years). Eighteen percent of their ears were found to contain excessive cerumen and to require ear canal irrigation. The incidence of abnormal tympanograms was high for young children but decreased with increasing age. A simple auditory speech perception test designed for use with both severely and profoundly deaf children is described, which provides for evaluation of a child's ability to recognize words, categorize them into stress patterns, or both. The children's word recognition and word categorization scores were found to relate to their audiometric averages. The overall test battery is easy to administer and also is efficient, in that considerable audiologic information can be obtained quickly.