No abstract

Metal Enhanced Fluorescence (MEF) typically produces enhancement factors of 10 to 50. By using a polymer layer as the dielectric spacer enhancements as high as 1,600 can be observed. The effect occurs with a variety of different polymers and substrates, all of which act to trap light in the dielectric layer. This allows the fabrication of sensors with improved sensitivity as demonstrated for detection of trinitrotoluene (TNT).

Speech intelligibility scores from 16 subjects with sensorineural hearing loss were evaluated using a digitized version of the California Consonant Test that was presented via headphones through a 300 to 3000 Hz bandpass filter to simulate the telephone band. Each subject was tested with an unprocessed signal that was frequency-equalized to compensate for the individual's hearing loss, and a signal that was equalized and compressed by the use of a compressor compression technique. Subjects were tested at three sound pressure levels above a pure-tone average threshold for frequencies 1 and 2 kHz. Two digital signal processing techniques designed to compensate for high-frequency hearing loss were examined: frequency domain processing and time domain processing. Frequency domain involved modification of the short-term spectrum obtained through a fast Fourier transform, whereas time domain processing involved passing the signal through a bank of finite impulse response filters. Both techniques showed significant intelligibility improvements (15-3070). In a second experiment, 16 additional subjects with high-frequency hearing loss compared an amplified telephone signal to three processed signals: (1) 6 dB per octave emphasis; (2) a signal frequency equalized for their hearing loss; and (3) a signal that was equalized for their hearing loss and was compressed according to their uncomfortable loudness levels. Most subjects preferred the signal with the 6 dB per octave emphasis. (Ear Hear 13 2:70-79)

This study is designed to determine whether or not traveling waves accompany harmonic distortion products generated in the cochlea, and also to describe the amplitude distribution of these nonlinear components. Cochlear microphonics were monitored with the differential electrode technique from the first and third turns of guinea pig cochleas. Cancellation of the distortion components was attempted by introducing boneconducted pure tones of the frequency of the harmonic and of controllable magnitude and phase. It was demonstrated that harmonic components can never be canceled simultaneously throughout the cochlea.It was shown that the reason for this inability to cancel is that harmonics are not distributed in the cochlea as their own frequency would indicate, but instead they are prominent in the region where their fundamentals are strong.