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Given at beginning of The Juergensmeyer Festschrift Symposium, Thursday, March 25, 2010 THE GREAT AMERICAN AUTHOR, WILLA GATHER, in her classic saga of the Great Plains, My Antonia, described an [...]

This research determined frequency importance functions (FIFs) for words, sentences, and continuous discourse under comparable conditions so that contextual effects of speech could be isolated. A male talker recorded 616 monosyllabic words, 176 meaningful sentences, and 44 continuous discourse (CD) passages. Twenty-four participants with normal hearing made intelligibility estimates of the CD passages and sentences and identified words in each of 44 low- and high-pass filtering and signal-to-noise ratio conditions. Plots of frequency versus percent of contributed intelligibility, or the FIFs, revealed that the frequency band that contributes the most to intelligibility is centered near 2000 Hz for all three types of speech. The results show a single peak in the importance function and a statistical analysis of the shape of the FIF (with kurtosis the pertinent measure) shows that there is a significant difference in the shape of the FIF based upon speech type. The data were also calculated into near-octave bands with similar results. The statistical analysis presented provides the basis for a test of the hypothesis: The degree of context or message redundancy is related to the relative importance of the frequency bands. The findings potentially have clinical as well as predictive implications. KEY WORDS: speech, perception, words, sentences, discourse

In 2004, a NOAA (National Oceanic and Atmospheric Administration) MF/HF radar or dynasonde was set up by the National Central University in Chung-Li (24.5°N, 121.0°E), Taiwan. The Chung-Li dynasonde employs an interferometric array (including four receivers) for receiving ionospherically reflected echoes, and is a fully digital research ionosonde, capable of providing high precision spatial and temporal ionospheric measurements. Utilizing a pulse set defined by four pulses transmitted at two closely spaced frequencies, the measured parameters are the time-of-flight and sixteen complex-amplitudes. Two types of observations are conducted by the Chung-Li dynasonde an active sounding mode and a passive sounding mode. The methods are utilized in observing the local ionosphere and RF environment above Chung-Li. The active sounding is capable of transmitting HF radio pulses for remote sensing of the ionosphere. Initial results from this study have revealed various special events for observing sporadic E and spread F, along with the distribution of foF2 in a single day. These initial results will be used to confirm the surveillance of the ionosphere from other instruments, and conduct statistical comparisons between seasons. On the other hand, passive sounding receives and records signals from RF environments. It is used to monitor the MF/HF band in real time, and is contrasted with the active results when the echo is weak.