Test-retest reliability of serial pure-tone audiograms in children at a school for the deaf

Otitis Media and Child Development

Otitis media with effusion (OME) is the major cause of auditory dysfunction in preschool and early-grade schoolchildren. At especially high risk are children with cleft palate/lip; some groups of mentally retarded children; children from underprivileged communities and children with severe or profound sensorineural hearing loss. In neonates the major concern is to identify those with severe sensorineural hearing loss but awareness of the likelihood of OME is also vital. The hearing loss associated with OME in its early stages may be as small as 10–15 dB and in consequence conventional hearing tests employing pure tones are inadequate as screening procedures. Acoustic impedance testing has proved to be a practicable, acceptable, sensitive and efficient method of identification of OME in infants and children. Impedance measurement cannot, as yet, provide accurate assessment of hearing loss, but this is probably not a serious drawback. The primary requirement is to detect OME in order that swift and effective treatment can be instituted.

Recognition of spectrally degraded and frequency-shifted vowels in acoustic and electric hearing

The present study measured the recognition of spectrally degraded and frequency-shifted vowels in both acoustic and electric hearing. Vowel stimuli were passed through 4, 8, or 16 bandpass filters and the temporal envelopes from each filter band were extracted by half-wave rectification and low-pass filtering. The temporal envelopes were used to modulate noise bands which were shifted in frequency relative to the corresponding analysis filters. This manipulation not only degraded the spectral information by discarding within-band spectral detail, but also shifted the tonotopic representation of spectral envelope information. Results from five normal-hearing subjects showed that vowel recognition was sensitive to both spectral resolution and frequency shifting. The effect of a frequency shift did not interact with spectral resolution, suggesting that spectral resolution and spectral shifting are orthogonal in terms of intelligibility. High vowel recognition scores were observed for as few as four bands. Regardless of the number of bands, no significant performance drop was observed for tonotopic shifts equivalent to 3 mm along the basilar membrane, that is, for frequency shifts of 40%-60%. Similar results were obtained from five cochlear implant listeners, when electrode locations were fixed and the spectral location of the analysis filters was shifted. Changes in recognition performance in electrical and acoustic hearing were similar in terms of the relative location of electrodes rather than the absolute location of electrodes, indicating that cochlear implant users may at least partly accommodate to the new patterns of speech sounds after long-time exposure to their normal speech processor.

Longitudinal study of hearing-disabled children. A follow-up investigation

A group of 138 hearing-impaired children, 76 boys and 62 girls, at a median age of 13 years, range 7-17 years, born during the period 1970-80, were examined in order to ascertain the incidence of progressive hearing loss, and if presence of progressive hearing loss relates it to specific causes of hearing impairment. After a 5-year interval from the median age of 8-13 years, progression of the hearing loss was demonstrated in 2-6% of the children (depending on the criterion used). No relationship could be established between progressive hearing loss and specific causes of hearing impairment.

Hearing disorders in childhood, some procedures for detection, identification and diagnostic evaluation

Hearing disability in childhood is a sign/symptom which should be detected, in order to avoid developmental disorders in language, speech, psychological and mental behavior. For proper treatment the hearing thresholds should be identified and the site of lesion evaluated in order to obtain a classification of the hearing loss. The causative factor(s) of the hearing disorder should be evaluated by means of an interdisciplinary cooperation. This review summarizes the results obtained in a series of investigations dealing with some procedures for detection, identification and nosological classification of hearing impairment in childhood. Based on these investigations a model for an examination program is proposed. This model requires interdisciplinary cooperation, preferably established at assessment centers. Prospective studies performed at these centers may offer precise data on the epidemiology of hearing disorders. Consequently preventive measures may be applied in order to reduce the number of children suffering from the symptom of hearing loss.

Conductive hearing loss effects on children's language and scholastic skills. A review of the literature

A review of available studies investigating the consequences of conductive hearing loss for language acquisition and scholastic performance was carried out. It uncovered no study that met the standards of rigor needed to provide a definitive answer to this question, although the burden of the evidence is that a persistent mild hearing loss, especially if present since infancy, probably has a measurably deleterious effect on the language of most but not all children. Diagnostic criteria documenting the severity, age of occurrence and duration of middle ear effusions were lacking. Measures of the detrimental effects of conductive losses on linguistic skills frequently were limited to the number of grades children were retained in school, their reading or vocabulary level on achievement tests, or a comparison of their scores on the verbal and performance scales of intelligence tests. Very few studies followed the acquisition of language in affected children or examined its structure. Very few considered the interaction between the socioeconomic and cultural environment of the child and the consequences of his hearing loss. The review underscored the need for prospective multidisciplinary studies in order to evaluate the actual impact of this common pediatric problem.