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T L Wiley

Publications and source records attributed to T L Wiley.

At least 37 records · Page 2Linked to original sources
PubMed1991

Consonant-recognition patterns and self-assessment of hearing handicap.

Two companion experiments were conducted with normal-hearing subjects and subjects with high-frequency, sensorineural hearing loss. In Experiment 1, the validity of a self-assessment device of hearing handicap was evaluated in two groups of hearing-impaired listeners with significantly different consonant-recognition ability. Data for the Hearing Performance Inventory--Revised (Lamb, Owens, & Schubert, 1983) did not reveal differences in self-perceived handicap for the two groups of hearing-impaired listeners; it was sensitive to perceived differences in hearing abilities for listeners who did and did not have a hearing loss. Experiment 2 was aimed at evaluation of consonant error patterns that accounted for observed group differences in consonant-recognition ability. Error patterns on the Nonsense-Syllable Test (NST) across the two subject groups differed in both degree and type of error. Listeners in the group with poorer NST performance always demonstrated greater difficulty with selected low-frequency and high-frequency syllables than did listeners in the group with better NST performance. Overall, the NST was sensitive to differences in consonant-recognition ability for normal-hearing and hearing-impaired listeners.

Adult↗
PubMed1989

Prostaglandin E2 induction of abortion and fetal demise.

Prostaglandin E2 (PGE2) suppositories have been shown to be active contractile agents and are effective in uterine evacuation for mid-trimester abortion or fetal demise. In this study, 85 patients were treated with vaginal PGE2 suppositories. When laminaria were used in patients with closed cervices, and compared to those who had minimal cervical dilatation, there was no difference in the time from induction to expulsion. Ninety-three percent of the 85 patients aborted successfully within 24 h. In each of the seven "failures", three or less suppositories were used prior to a dilatation and evacuation procedure. In this study, 81% of the abortions were complete, and in one-third of the remaining patients dilatation and curettage was performed just after delivery of the fetus. The incidence of minor side-effects ranged from 12 to 21%, and there were no major complications. It is concluded that the use of vaginal prostaglandin E2 suppositories for induction of mid-trimester abortion or fetal demise in the third trimester is safe and effective.

Abortion, Eugenic↗
PubMed1989

Static acoustic-admittance measures in normal ears: a combined analysis for ears with and without notched tympanograms.

A preliminary database of acoustic-immittance measures in normal adults was provided in an earlier publication (Wiley, Oviatt, & Block, 1987). Here, an additional analysis of static acoustic-admittance measures, based on the original database, is provided. Specifically, compensated static acoustic-admittance data for a 220-Hz probe signal are provided for 239 ears including those that did (N = 55) and did not (N = 184) demonstrate tympanometric notching for a 660-Hz probe signal.

Acoustic Impedance Tests↗
PubMed1987

Acoustic-immittance measures in normal ears.

A data base of acoustic-immittance measures in normal adults is presented. The subject pool consisted of 127 adults with normal hearing and a negative otologic history. Norms are presented for hearing thresholds, ipsilateral and contralateral acoustic-reflex thresholds, tympanometry, static acoustic-admittance measures, and middle-ear (tympanogram peak) pressure.

Acoustic Impedance Tests↗
PubMed1987

Tympanometric measures of eustachian tube function.

The purpose of this study was to develop instructions and procedures and to establish a normal data base for four tympanometric tests of Eustachian tube function: Valsalva, Toynbee, Inflation, and Deflation. Data were obtained for 24 young adults (48 ears) with normal hearing and normal middle-ear function. The tympanograms were analyzed for differences between baseline and experimental (postmaneuver) and baseline and posttest tracings for seven measures: tympanogram peak pressure, peak acoustic admittance, static acoustic admittance, negative gradient, positive gradient, and negative and positive acoustic-admittance values at +/- 400 daPa. The results indicated a statistically significant difference only in peak pressure for baseline and experimental tympanograms. Peak-pressure shifts were most pronounced for the Valsalva and Toynbee procedures. The small pressure shifts characteristic of the Inflation and Deflation procedures coupled with the potential for instrumental error severely limit the use of these procedures as means of obtaining reliable indices of tubal function.

Acoustic Impedance Tests↗
PubMed1986

Acoustic-reflex growth for multitone complexes.

The effects of activator spectral density on the growth characteristics of the acoustic reflex were evaluated in normal-hearing subjects. Reflex-growth dynamics were evaluated for computer-synthesized activators composed of 2 to 50 components and bandwidths wider and more narrow than the reported critical band for loudness summation. Although acoustic-reflex characteristics varied with activator bandwidth, there were no significant differences in reflex-growth patterns as a function of activator density (number of components). The findings suggest that, like loudness summation, growth or magnitude characteristics of the acoustic reflex are unaffected by the spectral density of the signal.

Acoustic Impedance Tests↗
PubMed1985

Acoustic-reflex dynamics and the loudness-discomfort level.

Acoustic-reflex growth functions and Loudness-Discomfort Level (LDL) measures were obtained for 15 normal-hearing subjects. The hypothesis that signals considered uncomfortably loud occur at intensity levels that produce proportionately equal acoustic-reflex magnitudes was evaluated. Individual reflex growth functions were measured as a function of activator SPL for a 1000-Hz tone, a 4000-Hz tone, and a broadband noise. These growth functions were measured within subjects (two trials) and across subjects in terms of (a) percentage acoustic-impedance change at LDL, (b) percentage acoustic-reactance change at LDL, (c) acoustic impedance at LDL, (d) relative change in acoustic impedance at LDL, and (e) ratio of static acoustic impedance to change in acoustic impedance at LDL. Although the loudness and acoustic-reflex measures demonstrated good reliability across trials, the data showed large variability across subjects and did not support the experimental hypothesis. It was concluded, therefore, that the use of acoustic-reflex measures in the estimation of an individual's LDL is unwarranted.

Acoustic Stimulation↗
PubMed1985

Frequency selectivity and consonant intelligibility in sensorineural hearing loss.

The relations between frequency selectivity and consonant intelligibility were investigated in subjects with sensorineural hearing loss in an attempt to derive predictive indices. Three matched pairs of subjects with similar audiometric configurations (high-frequency, flat or low-frequency hearing loss) but significantly different word-intelligibility scores were tested. Characteristics of psychophysical tuning curves (PTCs) for high- and low-frequency probes were compared with speech-intelligibility performance for high- and low-frequency consonant-vowel syllables. Frequency-specific relations between PTC characteristics and consonant-intelligibility performance were observed in the subject pairs with high-frequency and flat sensorineural hearing loss. Corresponding results for the subject pair with low-frequency sensorineural hearing loss were equivocal.

Adolescent↗
PubMed1985

Tympanometric and acoustic-reflex studies in neonates.

Tympanograms and acoustic reflexes for a broadband noise and for a 1000-Hz tone were measured in normal neonates. Notched tympanograms were typical of neonatal ears for a 220-Hz probe tone. A single-peaked tympanogram was most characteristic for a probe frequency of 660 Hz. Ipsilateral and contralateral acoustic reflexes were present more frequently for a 660-Hz probe tone compared to a 220-Hz probe tone, but acoustic-reflex thresholds were not significantly different between probe tones. As with adults, acoustic-reflex thresholds for the noise were significantly lower than for the tone, and ipsilateral reflex thresholds were lower than contralateral reflex thresholds. Reliability of acoustic-reflex and tympanometric measures was high. Age change from 2 to 4 days had no significant effect on tympanometric or acoustic-reflex characteristics. There was no apparent relation between tympanometric pattern and acoustic-reflex characteristics.

Acoustic Impedance Tests↗
PubMed1981

Dynamics of acoustic reflex growth.

Acoustic reflex growth was measured as a function of activator bandwidth in 10 subjects with normal hearing and in 5 subjects with different configurations of sensorineural hearing loss. The activators consisted of tones with frequencies of 500, 1 000 and 4 000 Hz, fractions and multiples of octave bands centered at these frequencies, and broadband noise. Growth functions for the normal-hearing subjects measured with a 660-Hz probe tone had smaller peak magnitudes and shallower slopes than the growth functions measured with a 220-Hz probe tone. The slope of the growth function and the peak magnitude of acoustic impedance were not affected in any consistent manner by activator bandwidth or activator center frequency. The dynamic range of the growth function increased with an increase in activator bandwidth beyond 1 octave. The resistive component of acoustic impedance did not exhibit a consistent pattern of change with increasing activator intensity level. The reflex growth functions for normal-hearing subjects separated into two groups, those with steep slopes and large peak magnitudes and those with shallow slopes and small peak magnitudes. 3 out of the 5 cases with sensorineural hearing loss presented growth functions with shallower slopes, smaller dynamic ranges and smaller peak magnitudes than normal. The other 2 cases had steeper slopes and larger peak magnitudes than normal. The dynamic range did not increase with an increase in activator bandwidth beyond 1 octave. The differences in reflex growth functions with probe-tone frequency observed for the normal group were diminished or absent in 4 of the 5 cases of sensorineural hearing loss. The frequency of 4 000 Hz appeared to be the most sensitive to reflex manifestations of hearing loss.

Acoustic Impedance Tests↗
PubMed1980

Temporal characteristics of auditory adaptation: a case report.

Auditory-adaptation, or tone-decay, measurements are reported for a patient with an 8th-nerve tumor in the left ear and a sensorineural hearing loss of cochlear origin in the right ear. Data for the patient suggested that the temporal features of auditory adaptation were more effective in differentiating adaptation processes for the two ears and associated lesions than was the magnitude classification of auditory adaptation in dB for the two ears. It is recommended that tests of auditory adaptation include an analysis of the temporal characteristics of the adaptation process.

Audiometry↗
PubMed1979

Acoustic-reflex growth and loudness.

Acoustic-reflex growth functions and loudness-balance judgments were obtained for three normal-hearing subjects with normal middle-ear function. The hypothesis that acoustic reflex-activating signals producing proportionately equal acoustic-impedance changes are judged equal in loudness was evaluated. The mean acoustic impedance and associated standard deviations were computed for the baseline (static) and activator (reflex) portions of each reflex event. An acoustic-impedance change exceeding two standard deviations of baseline was defined as the criterion acoustic-reflex response. Acoustic impedance was measured as a function of activator SPL for broadband noise and a 1000-Hz tone from criterion magnitude to the maximum acoustic impedance (or 120-dB SPL). This was defined as the dynamic range of reflex growth. Loudness-balance measurements were made for the 1000-Hz tone and broadband noise at SPL's representing 30, 50, and 70% of the individual dynamic range. The data supported the hypothesis.

Acoustic Impedance Tests↗
PubMed1979

Static acoustic-immittance measurements.

The basic principles of deriving static acoustic-immittance measurements in human ears are presented. Problems caused by differences in instrumentation, computations, and measurement technique are discussed in terms of the utility and comparisons of static acoustic-immittance measurements. Data are provided regarding the short- and long-term variabilities inherent to static measurements. Although our subject pool was relatively small, certain patterns were apparent in the short- and long-term variability inherent to static acoustic-impedance measurements. The intra-event variability about the mean static acoustic impedance was small and varied inversely with probe-tone frequency. Standard deviations were less than 50 acoustic ohms for a 220-Hz probe tone and less than 25 acoustic ohms for a 660-Hz probe tone. Session-to-session variability in static measurements varied little within subjects but varied greatly across subjects. There was little correlation between the mean and standard deviation for within-subject measurements. Standard deviations across subjects approximate a relatively constant proportion (30-40%) of the mean static value. The need for large population studies of static acoustic-immittance measurements is noted.

Acoustic Impedance Tests↗
PubMed1978

Acoustic-reflex dynamics for pulsed signals.

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

Acoustic Impedance Tests↗