Robert J. Ruben

Redefining the Survival of the Fittest: Communication Disorders in the 21st Century

Objectives: To determine the economic effect on the US economy of the cost of caring for people with communication disorders as well as the cost of lost or degraded employment opportunities for people with such disorders, including disorders of hearing, voice, speech, and language.

A Time Frame of Critical/Sensitive Periods of Language Development

By a focus on three essential elements of language, phonology, semantics, and syntax, a time frame for critical/sensitive periods of language development is presented as a model of central auditory nervous system flexibility. Several studies support the hypothesis that the critical/sensitive period of phonology is from the sixth month of fetal life through the 12th month of infancy. Data indicates that the critical/sensitive periods for syntax runs through the fourth year of life, and for semantics through the 15th or 16th year of life. The data indicate that there is a time dependent series of functions in sequence that is based on responsive adaptations made by the CNS to psychophysical and electrophysiological stimuli.

Plasticity of the Developing Auditory System

Anatomical, physiological and behavioral data indicate that the auditory system matures from the periphery centrally, ie, centripetally. There is now information which shows that the developing auditory system can be modified by anatomical changes which have their greatest effect during early development. Anatomical, physiological and behavioral changes can also be brought about by the quality of the auditory stimuli which the auditory system experiences. Evidence for the plasticity of the developing auditory system has come from studies of a number of different species. The plasticity of the auditory system is of theoretical and clinical significance.

Organ Culture of the Mammalian Inner Ear

An organ culture technique that is 90% effective has been established that will routinely allow the growth and development of the twelfth gestation day mouse inner ear. The in vitro development lags behind the in vivo development but follows the pattern of in vivo development.

Round window membrane delivery of L-methionine provides protection from cisplatin ototoxicity without compromising chemotherapeutic efficacy

Cisplatin (cis-diamminedichloroplatinum(II) (CDDP)) is a widely used, highly effective, oncolytic agent that has serious ototoxic side-effects. To test the effectiveness of local delivery, of L-methionine (L-Met) as an otoprotective agent against CDDP ototoxicity, we used a rat model of a highly metastatic breast cancer tumor, i.e. Fisher 344 rats implanted with MTLn3 breast cancer cells. Four experimental groups were evaluated--I: untreated; II: CDDP-treated (three dosages); III: systemically-delivered L-Met + CDDP-treated; IV: locally delivered L-Met + CDDP-treated. The integrity of the outer hair cells (OHCs) was determined using scanning electron microscopy (SEM); hearing was assessed by recording auditory brainstem responses (ABRs) at multiple frequencies. The chemotherapeutic effectiveness of CDDP was quantified by measuring changes in tumor mass and the presence of tumor metastasis. L-Met provided otoprotection of the OHCs against CDDP toxicity in the cochleae of rats following either systemic (III) or local (IV) administration. The ABRs were unchanged in each of the L-Met protection Groups (III and IV) and in the untreated animals of Group I. Treatment with CDDP only (II) induced significant hearing losses at both 16 and 18 kHz when compared to ABRs of untreated rats(I). CDDP was effective in controlling the MTLn3 initiated breast cancer tumors in the CDDP-treated (II) and the local L-Met protection, CDDP-treated (IV) Groups. In contrast, the tumors in the systemic L-Met protection, CDDP-treated Group (III) were not controlled by the CDDP treatment regime. This study demonstrates that local delivery of L-Met to the scala tympani of the cochlea via the round window membrane (IV) provides effective protection against CDDP ototoxicity without compromising its ability to control a highly metastatic form of cancer.

Recurrent middle ear effusion in childhood: implications of temporary auditory deprivation for language and learning.

Eighteen healthy, normal hearing (PTA≤15dB, better ear), neurologically intact, 8 to 11-year-old children who had documented histories of middle ear effusion (MEE) before the age of five years were evaluated by a battery of audiological, psychological, language and achievement tests. Each was compared to his/her non-MEE sibling who was tested at the same age. All the children (n = 36) tested in the bright normal range of verbal ability (WISC-R) and none had been diagnosed previously as learning disabled. Paired comparison of sibling data revealed that the effusion subjects had deficits in verbal ability, auditory decoding and spelling skills when compared with their control siblings. Significant strength in visual sequential memory in the MEE subjects suggests the availability of compensatory strategies for auditory deficits. Data analysis on the basis of sex and/or birth order differences could not explain the differences between siblings.

Otitis media, auditory sensitivity, and language outcomes at one year†‡

The relationship among otitis media, auditory sensitivity, and emerging language was examined in a group of 1‐year‐old children who were prospectively followed since birth. Pneumatic otoscopy was used to document the otologic status of the childrens ears at each medical visit. There were 13 babies with normal ratings in each ear at 80% more of their visits (designated as “otitis free”) and 12 babies with bilaterally positive otoscopy results at 30% or more of their first year visits (designated “otitis positive”). In comparison to the otitis free infants, the group of otitis positive babies demonstrated reduced auditory sensitivity as measured by auditory brain stem response (ABR) and poorer expressive language abilities. However, differences in receptive language were not detected. These results suggest that otitis media may have an impact on auditory sensitivity and developing language as early as 1 year of age.

Auditory consequences of early mild hearing loss associated with otitis media

Two groups of children received periodic documentation of their middle ear status by pneumatic otoscopy in the first year of life and had hearing sensitivity estimated by multiple auditory brainstem response (ABR) assessments during the same period. One group was considered otitis media (OM)-positive, with repeated bilateral episodes of OM and mild conductive hearing loss. The second group was considered OM-free with normal middle ear function bilaterally and normal hearing sensitivity in the first year of life. Childrens higher-order auditory abilities were examined at 4, 6 and 9 years of age. Various measures such as speech recognition-in-competition, visual-auditory learning, sound blending, auditory memory, and masking level difference estimates were utilized to probe the childrens auditory abilities. Results show that children with a first-year history of otitis media demonstrate deficits in the long term in some aspects of higher-order auditory processing. Performance appears to be associated with the mild hearing loss experienced during an important period of early development.

Auditory brain stem responses to bone-conducted tones in infants

The auditory brain stem responses (ABRs) to 500- and 2,000-Hz bone-conducted (BC) tones were recorded from 48 infants with ears exhibiting various external and middle ear states (normal, otitis media, auditory meatal atresia). Amplitudes were greater, wave V latencies longer, and detectability better for responses to 500-Hz BC tones compared to 2,000-Hz BC tones. Overall, most (94% to 100%) infants with normal cochlear sensitivity demonstrate ABRs to 20-dB normal hearing level (nHL) 500-Hz BC tones and 30-dB nHL 2,000-Hz BC tones. In cases in which masking is difficult (eg, bilateral atresia), infant ipsilateral/contralateral ABR asymmetries may help determine from which cochlea a response to the BC tones originates. In conclusion, two-channel ABR recordings to BC tones appear to be feasible for demonstrating normal cochlear sensitivity in infants.

Hypernasal Speech following Adenotonsillectomy

Extensive study of 120 patients with hypernasal speech following adenotonsillectomy showed that 48 had no evidence of abnormal speech prior to surgery and 41 had minor speech anomalies exacerbated postoperatively. Thirty-five patients had the classical stigma of submucous cleft palate and another 20 had occult submucous clefts. Fifty-seven of the patients had adenotonsillectomies because of recurrent middle ear effusions, but in the majority of these cases, recurrent middle ear disease continued even after surgery, probably secondary to palatal abnormalities.