Communal peeing: a new mode of flood control in ants.

The behavioral response of the obligate bamboo-nesting ant Cataulacus muticus to nest flooding was studied in a perhumid tropical rainforest in Malaysia and in the laboratory. The hollow internodes of giant bamboo, in which C. muticus exclusively nests, are prone to flooding by heavy rains. The ants showed a two-graded response to flooding. During heavy rain workers block the nest entrances with their heads to reduce water influx. However, rainwater may still intrude into the nest chamber. The ants respond by drinking the water, leaving the nest and excreting water droplets on the outer stem surface. This cooperative 'peeing' behavior is a new survival mechanism adaptive to the ants' nesting ecology. Laboratory experiments conducted with two other Cataulacus species, C. catuvolcus colonizing small dead twigs and C. horridus inhabiting rotten wood, did not reveal any form of water-bailing behavior.

Speech and language acquisition in young children after cochlear implantation.

Auditory and speech intelligibility scores of 22 prelingually profoundly deaf children who had used cochlear implants for between 1 and 7 years in an intensive auditory/oral educational program greatly exceeded those previously obtained from similar samples of deaf children using hearing aids. Half of the children obtained language quotient scores within the average range for normal-hearing children and the majority obtained reading quotients within 80% of normal levels. Normal levels of language and reading development were associated with early implantation and open set speech perception.

Speech perception and production skills of students with impaired hearing from oral and total communication education settings.

This study examined the degree to which students with profoundly impaired hearing who had been educated in oral and total communication (TC) environments developed auditory and speech skills. The sample consisted of 227 16- and 17-year-old students with profoundly impaired hearing: 127 from TC programs (63 with normal-hearing parents and 64 with deaf parents) and 100 from oral programs. Subject groups were matched in terms of age, unaided residual hearing, and IQ. On average, students from oral programs acquired more intelligible speech and made significantly better use of their limited residual hearing than did the TC students. This finding held for all TC students--those with deaf parents as well as those with normal-hearing parents. Although results of this study indicate that auditory and speech production skills are comparatively well developed in students who have consistently used spoken language throughout the day as the primary means of communicating, other factors associated with this oral sample, such as early amplification, consistent hearing aid use, early education, and parental support, may also be necessary for the development of good spoken language skills.

Educational management of children with cochlear implants.

During the last decade, the technology of assistive hearing devices for hearing-impaired children has improved significantly. Improvements in hearing aids and the introduction of cochlear implants and wearable tactile aids for children have made spoken language available to more deaf children and have changed the techniques for teaching listening and speaking skills. In June 1990, the Food and Drug Administration approved the Nucleus 22 channel cochlear implant for use with children. As a result, it is expected that more children will be implanted and, consequently, that the teachers and audiologist in the schools in which they are enrolled will need to learn to manage the devices. Since the Nucleus 22 cochlear implant does not restore normal hearing, children will continue to need instruction in listening and speaking. Furthermore, school personnel, who will be responsible for caring for and monitoring the implants, will have to learn how to maintain the devices. This article outlines some procedures for maximizing the benefits that profoundly deaf children can achieve with the cochlear implant.

Evaluating the benefits of cochlear implants in an education setting.

The material presented here summarizes the first year of a study to determine whether cochlear implants, tactile aids, acoustic hearing aids, or some combination of these are best for developing spoken language in prelingual profoundly deaf children. The effects of each device over and above the gains normally achieved as a result of oral instruction are examined. Each group contains three matched children, one fitted with each device, who are enrolled in the Central Institute for the Deaf (CID) school for 3 years of evaluation and training. This report describes results obtained from four groups of matched subjects during their first year in the study. These subjects improved in all areas evaluated, regardless of the device used. However, the implanted subjects exhibited a greater rate of progress in acquiring auditory speech perception skills. They exhibited no advantage in acquiring speech production skills and spoken language skills during their first year with the device. The subtle advantages provided by the implant may become apparent in spoken language development when 2- and 3-year post-test results are examined.

Predicting spoken language acquisition of profoundly hearing-impaired children.

The Spoken Language Predictor (SLP) Index is a proposed guide for making recommendations regarding the most appropriate communication mode to be used in educating a given hearing-impaired child. The SLP Index is the sum of points obtained on five predictor factors that have been weighted according to their contribution to successful spoken language acquisition. The point values assigned for each factor as well as assignment of points to particular test scores within each factor was accomplished by subjective clinical judgment followed by trial application to actual clinic cases. Three ranges of SLP indexes are associated with three educational recommendations: speech emphasis (SLP = 80-100), provisional speech instruction (SLP = 60-75), and sign language emphasis (SLP = 0-55). The purpose of this article is to describe the development and application of the SLP and preliminary evidence for its stability and validity.

Acquisition of spoken and signed English by profoundly deaf children.

A sample of 327 profoundly deaf children from oral/aural (OA) and total communication (TC) programs across the country was tested on the Grammatical Analysis of Elicited Language--Simple Sentence Level (GAEL-S), which measures production of selected English language structures. Results were analyzed separately for four different response modes: the oral productions of OA children, the oral productions of TC children, the manual productions of TC children, and the combined productions of TC children. Percentage correct scores for the oral productions of TC children were substantially below scores for their manual productions and below the scores of OA children in all grammatical categories sampled on the GAEL-S. The percentage correct scores of OA children were significantly higher than the manual and combined production scores of TC children in more than 50% of the grammatical categories. The manual scores of TC children significantly exceeded the scores of OA children in less than 20% of the categories. The gap between oral and manual production of the children in total communication programs indicates that spoken English did not develop simultaneously with manually coded English and that these children educated in programs using manually coded English did not develop competence with early developing English syntax at a rate faster than those not using signs.

Syntactic maturity of spontaneous speech and elicited imitations of hearing-impaired children.

Two language measures, designed for normal-hearing children, were applied to a sample of 52 severely and profoundly hearing-impaired children between four and 15 years of age. The Developmental Sentence Analysis (Lee, 1974) was used to assess their spontaneous language and the Carrow Elicited Languate Inventory (Carrow, 1974a) to assess imitated language. The correlation between scores on the two measures was similar to that found by Carrow (1974b) for normal children (r = .75). However, there was little relation between either measure and reading achievement in hearing-imparied children. A subsample of children retested one year later showed those who remained in a school for the deaf showed greater improvement in their ability to imitate while those who had been integrated into school with normal-hearing children improved most in spontaneous language. Over half of the hearing-impaired subjects scored below normal hearing three-year-olds on both measures. Caution is advised, however, in applying these norms to hearing-impaired children. The spontaneous language of these children differed from that of younger hearing children who received similar overall scores in the normative sample. The hearing-impaired subjects tended to use more mature constructions but used fewer correct structures per utterance.