At the first testing session, the mean score in background noise was 34.9% with CI alone (range 0-90%) and 41.1% with both devices (range 0-100%). Seven patients could recognize sentences in noise with CI alone, and four of them showed further improvement with added amplification. At the second session, at which all subjects could recognize sentences in noise with the CI alone, seven showed further improvement with added amplification. The mean score was 60.6% with CI alone (range 10-99%) and 75.5% with both devices (range 52-100%).

Spontaneous development of sound localization ability in totally deaf patients with unilateral cochlear implants is proportional to the time interval between implantation and initial testing. Improvement appears to be influenced by training, and to be greater in postlingual than in prelingual implantees.

Cochlear implants and conventional hearing aids use different stimulating signals. The beneficial effect of contralateral hearing aids in cochlear implantees, in terms of added speech perception, is still a matter of debate. The aim of this study was to evaluate the possible enhancement in speech perception in unilateral cochlear implantees who wear a conventional hearing aid in the non-implanted ear. Speech perception was evaluated after the patients had achieved a stable cochlear implant map and were comfortable with their binaural bimodal hearing. Patients and methodThe study participants were three post-lingually deafened adults and six prelingually deafened children with residual hearing in the non-implanted ear, in which they continued to wear a hearing aid after cochlear implantation. The duration of cochlear implant use and of concomitant use of cochlear implant and hearing aid are presented in Table 1.Speech perception tests were administered under three listening conditions: cochlear implant only, hearing aid only and cochlear implant plus hearing aid (Table 1). The post-lingually deafened adults underwent phonetically balanced monosyllabic word discrimination test, Spondee identification, CID sentence recognition in quiet background and CUNY sentence recognition in background noise (S/N +10 dB). The pre-lingually deafened children underwent phonetically balanced monosyllabic word discrimination test, Spondee identification, common phrase test sentences in quiet background and common phrase test sentences in background noise (S/N +10 dB). 52

By means of the results for phase shifts, differential cross-sections, and spin polarization in scattering of slow electrons from screened Hg, Xe and Ar nuclei the Motttheory is compared with its nonrelativistic approximation. For electron energies below 200 eV we find an increasing agreement of the results of the two theories with decreasing atomic number of the scatterer; for Ar both theories yield the same result.W.H. R6hl, Institut ffir Theoretische Physik der Universit/it K61n and Institut de Physique Nucl6aire, Division de Physique Th6orique, Orsay: The Deviation of the Magnetic Moments from the Schmidtlines Induced by a Nonlocal Two-Body Potential A unitary transformed two-body hard-core potential contains nonloeal terms, which will produce a deviation of the magnetic moments from the Schmidt-lines. These deviations were calculated for several nuclei up to Ca 41 using an oscillator basis, and they are positive for odd-neutron and negative for odd-proton nuclei. Thus it is not possible to describe the experimental deviation from the Schmidtlines; but for the magnetic moments of C 13, 015 and N is, the only nuclei where the experimental values are outside of the Schmidtlines, these nonlocal terms yield the right magnitude in the right direction of the deviation.A. Imbusch, I. Physikalisches Institut der Technischen Universit/it Berlin: t)ber den Einflufl der Oberfliichen diinner Schichten anf die Energieverluste schneller Elektronen in AI (The Influence of Surfaces on the Energy Losses of fast Electrons Traversing Thin Al-films The characteristic energy losses of electrons traversing thin Al-films were measured with high resolution. Especially their dependence on film thickness was investigated. To interpret satisfactory the observed dispersion of surface plasma loss retardation effects had to be taken into account. Furthermore, energy losses in the low energy part of spectrum, e.g. the intraband energy loss of A1, are shown to be surface losses in terms of the dielectric theory.