Little is known about the effects of contralateral acoustic stimulation on suppression tuning curves (STCs). Studies have examined the effect, but may have been confounded by activation of the acoustic reflex and the possibility of transcranial crossover of the contralateral signal. This study compared the sharpness (Q10 of STCs of SOAEs with and without contralateral stimulation that employed wideband noise. The intensity of the contralateral noise was well below the acoustic reflex threshold. The STCs of four female subjects were examined. The results revealed no change in the sharpness (Q10 of the tips of the STCs with and without contralateral stimulation. The lack of change in the STCs is inconsistent with prior findings based on recording obtained from single neurons in the auditory nerve in anesthetized animals and may reflect an insensitivity of the STC measures to dynamics of the efferent auditory system.

The purpose of this study was to assess the importance of communicative ability in the overall sociability of the older adult. It was hypothesized that the successful use of amplification by a hearing-impaired older adult would lead to an increase in communicative abillity and therefore sociability. A valid and reliable 35-item, two-part communicative ability and attitude sociability questionnaire was developed and administered to 50 older adults using a highly structured interview technique and fixed response set format. Part I of the questionnaire was constructed using a speaker-message-channel-receiver (SMCR) model as a conceptual framework and consisted of questions relating to a subject's communicative ability in social situations under a variety of listening conditions. Part II consisted of questions which sampled a subject's communicative attitude in social situations. / In addition to the sociability questionnaire, a hearing aid use and performance indicator form was developed. The objectives were to elicit information concerning subject satisfaction with the effects of amplification on communicative performance and to ascertain the actual amount of hearing aid use during the experimental treatment period. These data were analyzed for significant correlations between hearing aid use and sociability and between hearing aid performance and sociability. / In addition to assessing the importance of communicative ability in the sociability of older adults, "A Feasibility Scale for Predicting Hearing Aid Use (FSPHAU) with older individuals," developed by Rupp et al., was selected for further inquiry. The scale provides information regarding the probable effective utilization of amplification by an older adult. It seemed logical to assume that persons obtaining positive scores on the FSPHAU would also obtain high sociability scores if amplification was useful to them. Therefore, the hypothesis tested was that subjects obtaining positive FSPHAU scores would also obtain high communicative sociability scores after a period of successful hearing aid use. / If Rupp's FSPHAU is a helpful instrument in predicting the usefulness of recommended amplification, subjects who obtained a positive total score on the FSPHAU should also obtain positive hearing aid use and performance indicators. It was speculated that among all hearing-handicapped subjects provided with hearing aids, there should be a positive relationship between hearing aid use and FSPHAU total scores and between hearing aid performance and FSPHAU total scores. In addition, audiometric data related to auditory sensitivity and auditory speech discrimination ability were collected for comparison with self-report sociability questionnaire responses. / Results of this study led to the following conclusions: (1) Communicative ability is an important factor in the overall sociability of the older adult. (2) Concerning hearing-handicapped older adults provided with hearings aids, there is a positive relationship between hearing aid use and sociability and between hearing aid performance and sociability. (3) The FSPHAU appears to be a useful instrument in providing information related to the probable effective utilization of recommended amplification. (4) Hearing handicap can best be viewed from the standpoint of hearing sensitivity. / Source: Dissertation Abstracts International, Volume: 42-01, Section: B, page: 0131. / Thesis (Ph.D.)--The Florida State University, 1981.

The purpose of the present study was to determine the threshold (ART), latency, rate, and magnitude of the Acoustic Reflex (AR) for ten recorded environmental noise stimuli. These values were then compared to results obtained with standard white noise and a 1 kHz pure-tone. The latency was measured at threshold, and at 20 dB above the threshold (SL(,R)). The rate and magnitude were measured at 20 dB SL(,R). The measurements were made on 30 normal hearing subjects via an impedance meter. / The results, expressed in median values, suggested that: (1) The ARTs for the environmental noises ranged from 78.83 through 81.78 dB SPL. The ARTs for the white noise, and the pure-tone were 81.38 and 95.19 dB SPL, respectively. For all practical purposes (91%) the ARTs for the environmental noises lie within (+OR-) 5 dB of the ART for the white noise. (2) The latency at threshold for the environmental noises ranged from 452.5 through 552.50 msec. Similarly, the latencies were 402.5 and 487.5 msec for the white noise and the pure-tone, respectively. (3) The latency at dB SL(,R) for the environmental noises ranged from 152 through 180 msec. Similarly, the latencies for the white noise and the pure-tone were 152.5 and 181.0 msec, respectively. There was a decrease in latency at 20 dB SL(,R) compared to that at threshold across all the stimuli. (4) The contraction rate at 20 dB SL(,R) for all stimuli ranged from .0009 through .0011 cc/msec. (5) The contraction magnitude at 20 dB SL(,R) for all the environmental noises and the white noise ranged from .669 through .816 cc. However, the magnitude for the pure-tone was .867 cc which was higher than all the noises. / In conclusion, the answers obtained for the five experimental questions investigated provide data which is similar for the environmental noises and the white noise. / Source: Dissertation Abstracts International, Volume: 42-06, Section: B, page: 2296. / Thesis (Ph.D.)--The Florida State University, 1981.

This study deals with the hypothesis that ability of human observers to discriminate pitch of frequency disparate stimuli with short durations is predicted by temporal models at low frequencies. The upper frequency range for application of temporal models is explored and related to a two-process theory of pitch perception in which a temporal mechanism is dominant at low frequencies. The point of transition between mechanisms is estimated to be at or near 1000 Hz rather than in the range of 4000 to 6000 Hz as proposed in the literature. The results of this study also indicate that the contribution of the bandwidth-duration trading relationship for stimuli, as expressed in the frequency difference limen by duration relationship, does not fully account for short duration pitch discrimination. / Source: Dissertation Abstracts International, Volume: 43-02, Section: B, page: 0377. / Thesis (Ph.D.)--The Florida State University, 1982.

The behavioral masking level difference (MLD) has been established and incorporated into the central auditory processing test battery. Behavioral MLD literature states that the site of origin along the central auditory pathway is in the brainstem region. However, there has been some controversy when electrophysiologic measures have been performed during these types of behavioral MLD paradigms. Most electrophysiologic studies have focused on the late latency response (LLR) using small sample sizes (i.e. 10 subjects), and concluded that the origin of the MLD is cortical in nature. / The purpose of this study was to investigate and provide additional information, using a larger sample size (33 subjects), on the electrophysiologic MLD measures of the auditory brainstem response (ABR), middle latency response (MLR), and late latency response (LLR). Auditory evoked potential wave latencies and amplitudes were measured under both competing (broadband masker) and noncompeting conditions while using either a 500 Hz tone burst (3 msec rise/fall time with no plateau) or click signal. The phase of the signal was adjusted to be either in-phase or 180$\sp\circ$ out-of-phase at one ear. Behavioral MLDs were obtained beforehand using the identical stimuli as used during the evoked potential tests. A minimum 10 dB behavioral MLD was required. / Statistical significant differences, using ANOVA, were observed for in-phase/out-of-phase N1-P1 wave amplitudes of the LLR during competing conditions. No differences were observed for the MLR or the ABR during the same test conditions. However, significant differences were seen for waves I and V amplitudes during the noncompeting condition (phase difference) in the ABR. It was concluded that the only electrophysiologic measure showing the central auditory pathways participation during the MLD phenomenon was in the cortical region. However, this research using a larger sample size found fewer significant differences in the cortical region than those reported by previous researchers suggesting that studies of this nature and variability should be interpreted with caution before specific conclusions are made. / Source: Dissertation Abstracts International, Volume: 54-07, Section: B, page: 3538. / Major Professor: Lloyd L. Price. / Thesis (Ph.D.)--The Florida State University, 1993.

Research in word discrimination testing shows that performances vary as a function of the materials and procedures employed. The concept of phonemic regression, however, was based on a specific word list (PB-50) and sensation level (30 dB). The purpose of this investigation was to examine discrimination scores of individuals classified as phonemically regressed as functions of varying intensity levels and different word lists, and as compared to individuals not classified as phonemically regressed. The secondary issues addressed concerned the discriminatory error pattern differences between the two groups and whether a language deficit may be a contributing factor to phonemic regression. Each of 30 subjects was required to respond to two discrimination word lists (PB-50 and W-22) at several sensation levels (30, 40, and 50 dB). Based on pre-set criteria to identify those persons with phonemic regression, the subjects were divided into two groups and statistical analyses of intra- and inter- group scores were performed. For persons classified as phonemically regressed, statistically and clinically significant increases in discrimination scores were observed as the sensation level was raised from 30 to 40 and 50 dB. Furthermore, the W-22 word lists elicited higher performance scores than the PB-50 word lists. Inter-group results showed no significant differences in scores between the regressed and non-regressed groups at PB-max on the W-22 word lists. Limitations imposed by the test material and number of subjects prohibited the identification of specific differentiating error patterns. A trend of poorer language skills for the regressed group was noted. The results indicate that phonemic regression may be a product of the complex interaction of materials, procedures and hearing loss, rather than of anatomic and physiologic origin. The existence of phonemic / regression is not argued, rather caution is advised is attaching the phonemic regression label until all variables associated with discrimination testing, particularly the sensation level and word list utilized, have been manipulated. / Source: Dissertation Abstracts International, Volume: 44-11, Section: B, page: 3349. / Thesis (Ph.D.)--The Florida State University, 1983.

Stress is a generalized physiological response to environmental stressors. Of the hormone-triggered changes associated with the stress response, circulatory alterations were of particular interest to this research because they can reduce the blood supply to the inner ear and result in hearing decrements. / Because noise is an effective stressor, its effects on the body can be studied from that perspective. The "noise as a stressor" point of view was used in this research to answer the following question: Is a person's typical response to environmental stressors associated with his or her susceptibility to noise-induced hearing loss? / In order to answer this question, subjects were classified as either Type A or Type B on the Jenkins Activity Survey because it has been shown that Type A's exhibit stronger stress responses than do Type B's. Both types of subjects were exposed to a series of experimental conditions that were designed to differ in stressor magnitude. The stressors consisted of combinations of predictable or unpredictable 105 dB SPL noise bursts and a timed word task, designed to be a psychological stressor. / The hypotheses that predicted that Type A subjects who were exposed to unpredictable noise and had the word task to do would report more perceived stress and sustain more temporary hearing loss were not confirmed. However, the hypothesis predicting a relationship between degree of perceived stress and degree of temporary hearing loss was confirmed. Exploratory analyses, which went beyond the hypotheses, strongly suggested that the order of presentation of different noise conditions, and whether or not they were paired with a quiet session are important factors in the determination of both perceived stress and temporary hearing loss. This last finding has significant implications for the research design of future noise exposure studies. / Source: Dissertation Abstracts International, Volume: 44-07, Section: B, page: 2105. / Thesis (Ph.D.)--The Florida State University, 1983.

This study dealt with the relationship between an electrophysiologic response, a psychophysical response, and the perception of loudness. The electrophysiologic response of interest was the auditory brainstem evoked response. The psychophysical response of interest were those aspects of loudness perception related to the process of temporal summation and measured by the technique of loudness balancing. The relationship between these two responses was investigated by manipulating the temporal as well as the intensity characteristics of brief click stimuli used to obtain both responses. It was hypothesized that the auditory brainstem response is not directly related to loudness perception. Brainstem responses elicited with different click stimuli perceived as equally loud were therefore not expected to display similar characteristics. Auditory brainstem responses obtained from eight normal hearing young adult subjects supported this hypothesis. / Source: Dissertation Abstracts International, Volume: 48-02, Section: B, page: 0384. / Thesis (Ph.D.)--The Florida State University, 1987.

The study investigated the ability to visually perceive consonant stimuli during focused and divided attention and related these two lipreading measures to the visual contribution to bimodal speech perception under a fixed condition of auditory degradation. Thirty normal hearing young adults participated in the study. The test stimuli consisted of 22 consonants positioned medially between the vowel /a/. The VCV stimulus list contained four presentations of each stimulus item and was presented under four test conditions: audiovisual, auditory-only, visual-only and visual-with concurrent auditory processing. Percent correct scores were computed for all conditions and produced measures specifying (1) the visual contribution magnitude, (2) lipreading ability during focused attention and (3) lipreading ability during divided attention. / Results indicated that lipreading ability during focused attention was superior to lipreading ability during divided attention when performance was assessed under a progressively expanded homophenous-based scoring system. While subject performance was quite uniform during focused attention, performance variability was relatively large during divided attention. Correlations between visual contribution magnitude and lipreading ability during focused attention ranged from .308 to .486 across scoring systems and were significant under two of six scoring arrays. Correlations between visual contribution magnitude and lipreading ability during divided attention ranged from .623 to .675 and were significant under all scoring arrays. / The data indicate that lipreading ability during divided attention more accurately predicts the degree to which visual cues contribute to audiovisual perception of speech. The results are explained in terms of the effect of limited attentional capacity on dual-task processing. / Source: Dissertation Abstracts International, Volume: 45-09, Section: B, page: 2860. / Thesis (Ph.D.)--The Florida State University, 1984.

Bekesy audiometry was used to measure and evaluate the Most Comfortable Loudness (M.C.L), Uncomfortable Loudness (U.C.L.), and Aural Distortion levels of 20 normal listeners. / Both continuous (C) and Interrupted (I) pure tones, in a six octave sweep frequency mode, were presented to each subject. The resultant tracking patterns were classified as to Type and included Type I, Type V, and a Crossover Type. This crossover pattern is characterized by the C tone being tracked at lower intensities than the I tone at frequencies below 1500 Hz, at which it crosses over the I tracing and is tracked at a higher intensity for the remainder of the sweep. / A phenomenon of aurally generated distortion was seen to effect the type of pattern tracked at both suprathreshold levels. To evaluate this, the subjects were asked to track the threshold of perceived distortion and these levels were correlated with the tracking patterns. 100% of those subjects who tracked distortion levels at intensities lower than those of the C tone for either their M.C.L. or U.C.L. level had tracked a crossover/sloping pattern. Those subjects who reported either no perception of aural distortion or had perceived its onset at intensities greater than those of the C tone had tracked Type I/V patterns. It is hypothesized that if the subject allowed the C tone to enter into their area of aural distortion a spread of energy occurred resulting in an impression of decreased loudness, and the subject compensated by allowing the C tone to rise in intensity returning to the defined suprathreshold level. This resulted in the Crossover Type pattern. System harmonic distortion, time-order effects, and auditory fatigue were eliminated as significantly contributing factors. / The threshold of aural distortion was found to be perceived with stimulus on-times of between 200 to 300 msec. / The five subjects who reported no perception of aural distortion were able to track the onset of harmonic distortion when introduced into the system thereby eliminating attention and knowledge of the task as contributing variables. / Source: Dissertation Abstracts International, Volume: 42-03, Section: B, page: 0957. / Thesis (Ph.D.)--The Florida State University, 1981.