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Carbomethylcellulose (CMC) foam has been widely adopted to promote hemostasis and healing in sinus surgery. There has been interest in the use of CMC in middle ear surgery. The purpose of this study was to evaluate the safety and efficacy of CMC foam for use in middle ear surgery.Prospective, controlled.Academic research laboratory.Adult guinea pigs underwent experimental tympanoplasty followed by packing of the middle ear (n = 19 per group) with CMC, hyaluronic acid (HA), or gelatin sponge (GS). Auditory evoked brainstem response testing and otomicroscopy were performed before and serially for eight weeks after surgery. Tympanic membrane healing, hemostasis, and retention of packing material were assessed.All tympanic membranes treated with CMC healed by week eight. Less postoperative bleeding was observed with CMC than with HA or GS. Surgery elevated auditory thresholds, at least temporarily, in all groups. However, CMC was associated with greater auditory threshold elevation (15-25 dB) at eight weeks across all test frequencies relative to HA or GS (P0.01). Residual CMC and scarring were not found in the middle ear, indicating that the hearing loss was sensorineural. No head tilt posturing suggestive of vestibulopathy was seen.CMC was associated with hearing loss and may be ototoxic. Therefore, CMC should not be used in human middle ears given the presence of several nontoxic alternative materials.

Aspects of the auditory development of Gryllus bimaculatus are compared with those of other Orthopterans and Mantodea. Auditory receptor cell branching patterns and first-order auditory interneurones of last-instar crickets are morphologically very similar to adult cells; auditory thresholds are 30–45 dB higher in last instars than in adults; the ears of most ultimate nymphs lack directionality; and the tympana of last instars are not set apart clearly from the surrounding cuticle, are still thick, backed by a thick layer of epithelium, and lack microtrichia. Thus, the development of the auditory system from last-instar to adult shows close similarities between G. bimaculatus and Teleogryllus commodus but not to other Orthopteran or Mantid species. This supports the hypothesis that the pattern of post-embryonic development of the auditory system in crickets differs significantly from that in other Orthopterans and in Mantodea.

Absolute auditory thresholds, frequency resolution and temporal resolution develop with age. It is still discussed whether low-level auditory performance is of clinical significance—specifically, for delayed maturation of central auditory processing. Recently, five new auditory tasks were used to study the development of low-level auditory discrimination. It was found that the development lasts up to the age of 16–18 years (on an average). Very similar tasks were now used with 432 controls and 250 dyslexic subjects in the age range of 7–22 years. For both groups the performance in one of the tasks was not related to the performance in another task indicating that the five tasks challenge independent subfunctions of auditory processing. Surprisingly high numbers of subjects were classified as low performers (LP), because they could not perform one or the other task at its easiest level and no threshold value could be assigned. For the dyslexics the incidence of LP was considerably increased in all tasks and age groups as compared with the age matched controls. The development of dynamic visual and optomotor functions and the corresponding deficits in dyslexia are discussed in relation to the auditory data presented here. Copyright © 2004 John Wiley & Sons, Ltd.

Stapes surgery in relation to age This prospective study aims to evaluate the efficacy of stapedotomy in relation to age. Eighty-four ears of 82 consecutive patients who underwent stapedotomy were studied. Patients were divided into five groups according to their age. In each patient, we evaluated the pre- and postoperative auditory thresholds, according to the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology – Head and Neck Surgery guidelines. Statistically significant (P

Male Sprague-Dawley rats were exposed to ortho-, meta- or para-xylene by inhalation (450, 900 and 1800 p.p.m., 6 hr/day, 6 days/week for 13 weeks) and sacrificed for morphological investigations 8 weeks after the end of exposure. Brainstem auditory-evoked responses were used to determine auditory thresholds at different frequencies. Among the three isomers studied, only para-xylene produced moderate to severe ototoxicity in rats exposed at 900 and 1800 p.p.m. Increased auditory thresholds were observed at 2, 4, 8 and 16 kHz in rats exposed to 1800 p.p.m. para-xylene. The auditory threshold shifts (35 to 38 dB) did not reverse after 8 weeks of recovery. Moderate and severe losses of outer hair cells of the organ of Corti occurred in animals exposed to 900 and 1800 p.p.m. para-xylene respectively. Thus, the no observed effect level of para-xylene was 450 p.p.m. based on the loss of outer hair cells observed by light and electron microscopy.

Shifts in auditory intensity thresholds after salicylate administration were examined in postweanling and adult pigmented rats at frequencies ranging from 1 to 35 kHz. A total of 132 subjects from both age levels were tested under two-way active avoidance or one-way active avoidance paradigms. Estimated thresholds were inferred from behavioral responses to presentations of descending and ascending series of intensities for each test frequency value. Reliable threshold estimates were found under both avoidance conditioning methods, and compared to controls, subjects at both age levels showed threshold shifts at selective higher frequency values after salicylate injection, and the extent of shifts was related to salicylate dose level.

Objective: 1) To assess the feasibility of a computer-based closed-response speech test (CRST) in the ENT clinic. 2) To compare a closed response speech test to standard speech audiometry.Method: Thirty patients underwent otoscopy, tympanometry, pure-tone audiometry, speech audiometry and a closed-response speech test (CRST). For the CRST, patients were asked to choose, on a tactile computer screen, the words that were presented to their ear, amongst a choice of 4 words. Fifteen sets of 4 words were used.Results: The CRST was well accepted by all patients, whatever their computer literacy, but took significantly longer (10 to 15 minutes per ear) than speech audiometry did. Pure transmission hearing losses showed a translation of the performance intensity function toward greater intensities, without change in slope, as in standard speech audiometry. Correlations between auditory thresholds and speech recognition thresholds were greater for the CRST (r = 0.70, P < .01) than for speech audiometry (r = 0.46, ...

Objective: Determine if intraoperative electrocochleography (ECoG) during cochlear implant (CI) surgery provides online feedback to the surgeon to modify surgery and reduce trauma for increasing preservation of residual hearing.Method: Seventeen adult patients undergoing CI who had measurable auditory thresholds preoperatively in the low- to mid-frequencies were enrolled. Eight subjects had intraoperative compound action potentials (CAPs) measured to assess cochlear function during surgery. In those patients, surgery was modified according to ECoG feedback. Nine subjects performed CI without ECoG feedback.Results: The average preoperative PTA thresholds (0.25-2 KHz) were 76 ± 9 and 84 ± 12 dBHL in the unmonitored and monitored cohorts, respectively (P > .05). CAPs recording showed latency shift (0.5-1.5msec) and normalized amplitude deterioration (10%-50%) during surgery. All these changes reverted to normal after electrode insertion in all but one subject. The average postoperative PTA threshold shifts (...

Objectives: Many cochlear implant candidates have measurable hearing prior to implantation. Recent reports indicate that residual hearing can be preserved. By comparing pre- and postimplantation auditory thresholds, this study examines the Texas Children’s Hospital experience with conservation of residual hearing. Methods: Children with bilateral profound sensorineural hearing, implanted at least 6 months prior to this study, were eligible for enrollment. A multi-channel device was implanted by the same surgeon in each patient using a round window approach. Preimplantation auditory steady-state responses (ASSR) were available for each patient. Postoperative ASSR were obtained and compared to preimplant thresholds. The nonimplanted ear served as control. Results: Twelve patients (mean age, 4.9 years; 42% male) were studied. Paired t tests indicated no statistically significant differences (P < 0.05) between the pre- and postimplant ASSR thresholds at 250, 500, 1k, 2k, 4k, and 8k Hz in the implanted ear. There was no difference (P < 0.05) over the same time period for ASSR thresholds in the nonimplanted control ears at the same frequencies. Conclusion: With the use of a round window approach, by 6 months postimplantation, there is no statistically significant change in auditory function in the implanted ear. Furthermore, by using the nonimplanted ear as a control, this study demonstrates the ASSR to be a stable measure over time. Preservation of residual hearing requires serious consideration as technological advances in electrode development and changing selection criteria for implantation occur.

The effects of reduced auditory feedback were investigated using an accurately calibrated binaudal pure tone producer on 27 stuttering children and 68 non-stuttering controls. A comparison was made of both auditory hearing and discomfort thresholds in the two groups; the hearing thresholds did not differ between the groups. The results did however replicate an earlier finding which suggested that stutters have a lower threshold for auditory discomfort than do normal speakers, and showed that fluency is inversely related to auditory feedback. The discussion suggests that a necessary cause of stuttering is a physiological abnormality in side-tone conduction and central processing.

Auditory thresholds were determined by a modified method of limits, in introverts, ambiverts and extraverts, under three intensities of light. Five determinations were made: one before, one during and three (30 sec., c. 8 and 16 min.) after the light stimulation. An analysis of variance of the data showed significant results for the interval conditions, the personality type and the interaction of these parameters, under the weak light. Interval effects were also significant under medium and strong light. A weak light increased, and a strong light decreased, auditory sensitivity when threshold determinations began 30 sec., but not more than about 8 min., after the light stimulation, in introverts.

A simple and efficient method of estimating points on the psychometric function, and thus of estimating absolute and difference limens, is described. An illustration of the method is given in which sensitivity to inter-aural time differences is measured.

Postmeningitic hearing loss is often bilateral, profound, and rapid in onset. Children with postmeningitic hearing loss may be identified as potential candidates for cochlear implantation. The length of time required for a definitive trial with conventional amplification, which must precede a final decision regarding cochlear implant surgery, has been the subject of debate. Twenty-five children with bilateral severe-to-profound postmeningitic sensorineural hearing loss were fitted with appropriate amplification and results of serial-aided tests were analyzed to determine the degree of benefit and changes in aided thresholds over time. Twelve children gave aided responses that clearly indicated the presence of residual hearing and good aided benefit. Ten youngsters have responded consistently in the vibrotactile range when aided, thus receiving limited benefit from conventional amplification. Of particular interest are three children who initially exhibited limited or no auditory responses but who, after a period of 16 to 25 months, showed excellent benefit with binaural hearing aids. These children are all in total communication programs and have received good auditory training. Caution should be exercised when concluding that such a child does not benefit from amplification.

For many years (auditory) middle latency response (MLR) reportedly has been an excellent electrophysiological procedure for estimating frequency specific auditory thresholds. Currently the 40 Hz potential, a derivative of the MLR, holds even greater promise for threshold testing. MLR also appears to have potentially valuable applications in the evaluation of functional hearing loss and assessment of higher auditory function. However, MLR is not without controversy. Questions of origin, filtering effects, and its use in pediatric assessment are current issues surrounding applications of MLR. The following article analyzes the values and limitations of MLR within the framework of past, present, and future research and clinical uses.

Following meningitis, 280 children (168 boys, 112 girls) had audiological assessment, and 87 (31%) were initially found to have a sensorineural hearing loss in one or both ears. Twenty-three children were followed elsewhere. Of 64 children followed for an average of 3.46 years, 55 (86%) exhibited stable auditory thresholds over time, most commonly (24) bilateral, profound/anacusic losses. One moderate and four severe losses were identified, but no bilateral, mild losses. Nineteen children had asymmetric losses with varied audiometric configurations. Seven children presented with a unilateral hearing loss, again with a range of configurations. Auditory thresholds changed over time in nine children, either improving, declining, or fluctuating, over a variable interval ranging from 1 month to 12 years.

The American Hearing Research Foundation has developed a regional Infant Screening Program in the state of Illinois, designed to meet the vital need for early identification of hearing impairment on a mass scale. The four major components of the program include: 1. Application of the High Risk Register to the general newborn population, 2. Hearing Screening in the Intensive Care Nursery, 3. Electrophysiologic confirmation with Brain Stem Electric Response testing and 4. Subsequent and immediate remediation and/or habilitation. Brain Stem Electric Response Audiometry (BERA) has been shown to be an accurate and sensitive clinical tool for obtaining auditory thresholds in infants from birth. At the Donald T. Forsythe Otologic Laboratory in Mercy Hospital, Chicago, IL, over 250 infants and young children have been tested in a controlled study with BERA to establish or rule-out the diagnosis of hearing impairment. The use of BERA preceded by screening of a refined neonatal population has proven to be an effective method of early identification. The goals of the program are: 1. To identify hearing impaired children prior to passage of the critical periods, 2. To medically or surgically classify and treat and/or auditorily habilitate, and 3. To ultimately improve the quality of life of the child born with hearing impairment.

The author visited Duren, West Germany and evaluated the performance of five patients implanted with the extracochlear Duren/Cologne implant who achieved better word recognition levels. Word and sentence speech reception tests were presented live-voice by a familiar German speaker. Performance ranged from 1% to 80% correct word recognition with sentence material, 0% to 63% correct word recognition with word lists, and 13% to 86% correct recognition for phonemes in words. One patient achieved high-level, open-set word recognition without visual cues, using single-channel, extracochlear stimulation. Preimplant auditory thresholds in her implanted ear were 60, 65, 90, and 105 dB HL at octave frequencies from 125 to 1,000 Hz, respectively. There was no measurable hearing at higher audiometric frequencies.