Individual Tapes Research Articles

Changes in Apparent Extent of Misarticulation during Successive Repetitions of a Word

This study investigated the variability of judgments of correct and misarticulated /r/ words. Correct, moderate, and severely distorted /r/ words were each repeated 90 times on individual audio tapes and judged by listeners from one of three groups ( N = 33). Subjects in each group showed shifts in judgment but the group which evaluated the severely distorted /r/ word demonstrated the most frequent shifts in judgment.

THE IMITATIVE RANGE OF THE SONG OF THE MARSH WARBLERACROCEPHALUS PALUSTRIS, WITH SPECIAL REFERENCE TO IMITATIONS OF AFRICAN BIRDS

SUMMARYThis paper presents the first extensive evidence of vocal imitations of African birds by a Palaearctic migrant, the Marsh WarblerAcrocephalus palustris. Nearly 30 individual tape recorded repertoires have been analysed, most of them from Belgium; imitations of each identified species were compared to models by spectrographic analysis. A list of 113 African species (33 non‐passerines, 80 passerines) was thus established (Appendix), which, added to the list of 99 European species, gives a total imitative range of 212 species. The low‐pitched voices of many non‐passerines exclude them from imitation.Vocal imitations of some rather local species in East Africa provide information on the localization of the autumn and winter quarters ofA. palustris. In particular, the frequency of imitations of such species as Vinaceous DoveStreptopelia vinacea, Boran CisticolaCisticola bodessaand Red‐pate CisticolaC. ruficepslends support to the idea of the existence of autumn quarters in northeastern Africa.Individual repertoires contain an average of 76.2 different imitated species (extremes 63–84), the number of African species (average 45.0) exceeding that of European species (average 31.2). About a fifth of the complete song remains unidentified and probably corresponds to imitations of African birds whose voices have not yet been recorded. The most recurrent imitations are those of noticeably noisy species, widespread in Africa.A. palustrisappears not to be selective in its repertoire. Imitations of different species can, to some extent, be combined and alternated into original motifs.Circumstantial evidence indicates that the youngA. palustrisare still learning song motifs when on their way to their winter quarters and probably stop learning soon after their arrival there, most of them in January, at the age of 6–7 months. There is a temporal separation between the sensitive phase and the motor phase of song learning.No conclusion as to the possible functions of the imitative element of the song can be drawn at present.

A Course for Foreign Students at a Small College

American Culture and Language, a course for foreign students at Berea College, combines listening, speaking, composition, and orientation. Lectures by staff members from various departments of the college, on topics which will help students adjust academically and socially, form the nucleus of the course. Discussions and written assignments are based on these lectures. Extensive use is made of the language laboratory, and the students' progress in speech is checked by using individual tapes and a tape recorder. Within the framework of lectures and class discussions related to orientation, students are given help in both speech and writing according to their individual needs.

Tracking Resistance of Insulating Tapes for Taped-Type Terminations

Nineteen commercial tapes used for covering insulation in terminations were tested for tracking resistance. Accelerated test results are given for dust-and-fog, endurance wheel, and dip-track tests. While all tests rated classes of materials in the same order, correlation of ratings of individual tapes proved difficult. Vinyls readily tracked, polyethylenes and butyls were more resistant, and silicone rubbers showed least tendency to track.

A New Method of Investigating Cable Deterioration and Its Application to Service Aged Cable

Investigation of the radial variation in electrical and chemical characteristics of cable insulation between conductor and sheath is suggested as a valuable means for throwing new light on cable'deterioration in service. An apparatus is described for the rapid accurate measurement of power factor of individual paper tapes taken from cable. A method is given for determining the total oxidation products in the oil from the paper tapes, layer by layer, from sheath to conductor. The results obtained by applying these methods to several types of service aged cable are reported, together with the indications which they give of the relative importance of ionization and oxidation as aging factors.

A new method of investigating cable deterioration and its application to bervice-aged cable

IINVESTIGATION of the radial variation in electrical and chemical characteristics of cable insulation between conductor and sheath is suggested as a valuable means for throwing light on cable deterioration in service. A cell is described for the rapid accurate measurement of power factor of individual paper tapes taken from cable. A method is given for determining the total oxidation products in the oil from the paper tapes, layer by layer, from sheath to conductor. The results obtained by applying these methods to several types of service-aged cables are reported, together with the indications which they give of the relative importance of ionization and oxidation as aging factors.