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Audiometric results of bilateral bone-anchored hearing aid application in patients with bilateral congenital aural atresia.

The effect of bilateral application of bone-anchored hearing aids (BAHAs) was examined in terms of directional hearing and speech recognition in quiet and in noise in four patients with bilateral congenital atresia who, out of pure necessity, had been using a unilateral bone-conduction hearing aid since early life. This study comprised a prospective clinical evaluation in a single subject design; four patients with bilateral congenital atresia originating from the Nijmegen BAHA series participated. Three patients had Treacher Collins syndrome. All four patients had conductive, most probably, symmetrical, hearing loss. Recently these patients had applied for a second BAHA and were subsequently fitted bilaterally. With two BAHAs, all four patients showed significant improvement in sound localization. Also, speech perception in quiet showed significant improvement with bilateral application, and a significant improvement was found in speech perception in noise in three patients. These results suggest that patients with congenital conductive, symmetrical hearing loss will benefit from bilateral BAHAs.

Adolescent↗

Stapedectomy in patients with small air-bone gaps.

Controversy exists concerning stapedectomy for patients with small air-bone gaps. The purpose of this study was to examine the results for patients who had a stapedectomy to correct a small (10 dB or less) air-bone gap. One hundred fifty-four patients with suspected otosclerosis were explored and a stapedectomy was performed in 136 (88.3%) of these cases. The mean pure-tone average (PTA) improved 16.7 dB and overdosed the preoperative bone conduction PTA by 8.1 dB. The majority of the stapedectomy patients (89.7%) had a PTA closure greater than or equal to 0 dB. These results showed that stapedectomy can be an effective procedure for eliminating and overdosing even small air-bone gaps due to otosclerosis.

Audiometry, Pure-Tone↗

Incapacitating hypersensitivity to one's own body sounds due to a dehiscence of bone overlying the superior semicircular canal. A case report.

We present a case study of a 49-year-old patient with an 8-year history of hypersensitivity to sound produced by intrinsic but not extrinsic sources. Findings that indicated an organic problem were: a supranormal bone conduction threshold of -25 to -15 dB HL from 0.25 to 1 kHz with an air-bone gap of 15 to 45 dB HL, a lower threshold and larger amplitude for vestibular-evoked myogenic potentials, eye movement reactions to sound and trunk pitch sway in response to sound. Results of immitance audiometry and otoacoustic emission testing were within normal limits and indicative of intact middle ear conductance. A high-resolution CT scan of the temporal bone demonstrated a dehiscence of bone overlying the superior semicircular canal. These findings support previous research indicating that auditory energy reaches the cochleo-vestibular receptor systems more easily via transmission through cerebrospinal fluid than through bone. Therefore, a dehiscence of the bone overlying the superior semicircular canal may lead to hypersensitivity to intrinsic sound. We recommend that similar findings in other patients be followed up with an evaluation of middle ear function and the temporal bone with high-resolution CT scan.

Bone Conduction↗

[Comparative speech audiometry studies with compact disk].

We compared the results of speech audiometry, performed with recorded tape and CD, respectively, in 21 subjects with bone conduction hearing loss, and in 27 subjects with sensorineural hearing loss. In all cases, speech audiometry was performed by using the German Freiburg speech test material, recorded in 1969 on the basis of the German DIN standard 45626. In subjects with an air-bone gap, the hearing loss for speech is 2.3 dB smaller if tested by use of CD, and the speech recognition is 10.5 points better, respectively. Smaller differences could be found in sensorineural HL: For CD, the hearing loss is 1.2 dB smaller, and the speech recognition score is raised by only 1 point. These differences are statistically not significant, and the calculation of hearing impairment and individual hearing handicap from the tables commonly used in Germany in medicolegal expert opinions must not be corrected, if records on CD are used basing on the recordings from 1969 according to DIN 45626. The handling of compact discs has many advantages in relation to the handling of tapes.

Adult↗

Hearing results with the Dornhoffer ossicular replacement prostheses.

The "ideal" prosthesis for ossicular reconstruction should, from a surgical standpoint, require easy manipulation, reduce surgeries to partial or total variants, and be constructed of stable, biocompatible material. From an acoustic standpoint, a prosthesis should weigh 10 to 40 mg, provide proper tension between the tympanic membrane (TM) and stapes, form less than a 30-degree angle with the TM, and accommodate the malleus. Work was conducted with Smith & Nephew Richards, Inc. (Memphis, TN), to develop a partial ossicular replacement prosthesis (PORP) and a total ossicular replacement prosthesis (TORP) that combined the majority of these features. This retrospective study used a computerized otologic database to identify patients implanted with a Dornhoffer HAPEX PORP or TORP from June 1995 to March 1997. The surgical procedures utilizing these prostheses were primary cholesteatoma and revision surgery of previously performed modified or radical mastoidectomies complicated by poor hearing or chronically draining cavities. Preoperative and postoperative air and bone conduction four-frequency (500, 1000, 2000, and 3000 Hz) pure-tone averages (PTAs) were used to calculate the PTA air-bone gaps (ABGs). Results in 52 cases (follow-up, 1 year) showed a statistically significant improvement in hearing (P < 0.05) for each group. Excellent hearing results (< or = 10 dB PTA-ABG) were seen in 69% of PORP cases and in 35% of TORP cases, and good results (11 to 20 dB PTA-ABG) were seen in 31% and 50% of PORP and TORP cases, respectively. Designing an ossicular replacement prosthesis with both surgical and acoustic factors in mind has led to encouraging short-term hearing results.

Acoustics↗

Effects of estrogen therapy on hearing in postmenopausal women.

OBJECTIVE: This study was undertaken to investigate how hormone therapy affects hearing in postmenopausal women. STUDY DESIGN: This prospective study involved 109 postmenopausal women. Twenty of the women were using estrogen therapy (ET group), 30 women were using hormone therapy (HT group), and 59 had not received hormone therapy of any kind (control group). Otoscopic examination revealed normal tympanic membranes in all 109 subjects. Each individual was tested with low- (250-2000 Hz) and high-frequency audiometry (4000-16000 Hz). Duration of hormone therapy was recorded, and patient characteristics (age, type of menopause, time since onset of menopause), body mass index (BMI), and hearing test results in the ET, HT, and control groups were compared. RESULTS: There were no statistically significant differences between the treatment (ET and HT group) and control groups with respect to age, BMI, or time since onset of menopause. The mean time on HT and ET was 4.13+/-2.41 years and 3.35+/-2.20 years, respectively. The mean air conduction results at low frequencies (250, 500, 1000, and 2000 Hz) in the ET group were significantly higher than the corresponding findings in the control group (P<.001) and than the HT group (P<.001). When the same comparisons were made between the HT group and the control group, none of the differences was statistically significant (P>.05). The mean air-conduction results at high frequencies (4, 6, 8, 10, 12, 14, and 16 kHz) in the ET group were significantly higher than the corresponding results in the HT group (P<.008). ET versus controls and HT versus controls at high frequencies revealed no significant differences (P>.05). The mean bone conduction results in the ET group were significantly higher than the corresponding findings in the control group (P<.016). Analysis of the same comparisons between the HT-ET and HT-control groups revealed no significant differences (P>.05). CONCLUSION: Estrogen therapy may slow down hearing loss in aging postmenopausal women; however, further studies of larger series are needed to confirm this, and the sites of hormonal action must also be explored.

Audiometry↗

Recent changes in audiometric standards.

A number of new British Standards have been published which affect users of audiometers and audiometric calibration equipment. These are identical to their international counterparts, giving us agreed values for thresholds of hearing by both air and bone conduction. This article draws attention to the important changes that have taken place and looks forward to likely future changes.

Audiometry↗

[Otosclerosis: surgical improvement of hearing and primary labyrinthine efficiency (author's transl)].

The result of stapedectomy in which the stapes were replaced by a Schuknecht prosthesis is examined on the basis of 156 audiograms. Of particular interest is the connection between the degree of restored hearing through surgery and the preoperative bone-conduction hearing loss. The degree of restored hearing can be proved to be independent of the preoperative performance of the inner ear, which means that in patients with a higher degree of inner-ear involvement the raising of the air-conduction hearing threshold is achieved in the same way as in patients without inner-ear involvement.

Adult↗

Restoration of binaural hearing with the audiant implant following acoustic neuroma surgery.

Experience with the use of The Audiant Bone Conductor hearing implant in 8 patients who had unilateral profound hearing loss following acoustic neuroma surgery shows it to beneficial. Patients must have good hearing by bone conduction in the opposite uninvolved ear to be a candidate. Patients with unilateral hearing loss have the choice of doing nothing and getting along with one ear, they may be fitted with a CROS (contralateral routing of the signal) hearing aid or they may use the bone conductor hearing implant. Our experience suggests that patients prefer the bone conductor hearing implant since the resulting binaural hearing sounds more natural and an instrument needs to be worn on only one side. A surgical technique and new instrumentation to minimize the size and extent of the surgeries is described. The surgical implantation is usually done one month after acoustic neuroma surgery and is performed under local anesthesia in the outpatient surgery.

Bone Conduction↗

Underwater hearing and sound localization with and without an air interface.

HYPOTHESIS: Underwater hearing acuity and sound localization are improved by the presence of an air interface around the pinnae and inside the external ear canals. BACKGROUND: Hearing threshold and the ability to localize sound sources are reduced underwater. The resonance frequency of the external ear is lowered when the external ear canal is filled with water, and the impedance-matching ability of the middle ear is significantly reduced due to elevation of the ambient pressure, the water-mass load on the tympanic membrane, and the addition of a fluid-air interface during submersion. Sound lateralization on land is largely explained by the mechanisms of interaural intensity differences and interaural temporal or phase differences. During submersion, these differences are largely lost due to the increase in underwater sound velocity and cancellation of the head's acoustic shadow effect because of the similarity between the impedance of the skull and the surrounding water. METHODS: Ten scuba divers wearing a regular opaque face mask or an opaque ProEar 2000 (Safe Dive, Ltd., Hofit, Israel) mask that enables the presence of air at ambient pressure in and around the ear made a dive to a depth of 3 m in the open sea. Four underwater speakers arranged on the horizontal plane at 90-degree intervals and at a distance of 5 m from the diver were used for testing pure-tone hearing thresholds (PTHT), the reception threshold for the recorded sound of a rubber-boat engine, and sound localization. For sound localization, the sound of the rubber boat's engine was randomly delivered by one speaker at a time at 40 dB HL above the recorded sound of a rubber-boat engine, and the diver was asked to point to the sound source. The azimuth was measured by the diver's companion using a navigation board. RESULTS: Underwater PTHT with both masks were significantly higher for frequencies of 250 to 6000 Hz when compared with the thresholds on land (p <0.0001). No differences were found in the PTHT or the reception threshold for the recorded sound of a rubber-boat engine for dry or wet ear conditions. There was no difference in the sound localization error between the regular mask and the ProEar 2000 mask. CONCLUSIONS: The presence of air around the pinna and inside the external ear canal did not improve underwater hearing sensitivity or sound localization. These results support the argument that bone conduction plays the main role in underwater hearing.

Acoustic Impedance Tests↗

[Hearing results after anterior tympanotomy in cholesteatoma surgery].

Between 1987 and 1993, 71 ears of attic type cholesteatoma and 20 ears of adhesive type were operated on using the intact canal wall technique combined with anterior tympanotomy. Pre- and postoperative pure tone hearing after the surgery were analyzed, especially to determine whether anterior tympanotomy is harmful to the inner ear. Mean values of 500, 1000 and 2000Hz of air conduction threshold immediately, before and about 1 year after the operation were compared. In attic cholesteatoma, type 1, type 3, and type 4 of ossiculoplasty revealed significant improvement of 8.4dB, 9.3dB, and 8.0dB respectively. In adhesive cholesteatoma, results obtained were 8.4dB, 0.8dB, and -3.0dB. Differences between pre- and postoperative bone conduction threshold at 4000Hz were 1.5dB in type 1, 1.3dB in type 3, and 5.0dB in type 4 in attic cholesteatoma. Those in adhesive cholesteatoma were -2.5dB, -0.2dB, and -10.0dB respectively. From the results obtained, we concluded that (1) our results were satisfactory with regards to hearing ability following all types of ossiculoplasty in attic cholesteatoma and in type 1 in adhesive cholesteatoma, (2) anterior tympanotomy itself is not a harmful procedure to the inner ear in both types of cholesteatoma, (3) an increase in bone threshold in adhesive cholesteatoma is due to the surgical procedure at the stapes and/or the oval window.

Adolescent↗

Hearing results of canal wall reconstruction tympanoplasty for middle ear cholesteatoma in children.

OBJECTIVE: To investigate post-operative hearing results in children with middle ear cholesteatoma, and to analyze the correlation between hearing results and clinical factors and findings before and during the operation. PATIENTS AND METHODS: One hundred and twenty-four ears of 123 children were operated on for middle ear cholesteatoma at the age of 10 years or younger by canal wall reconstruction tympanoplasty and were followed up more than 1 year after the final operation. We evaluated the average air and bone conduction hearing levels at the speech ranges before the first operation (pre-operative hearing) and after the final operation (post-operative hearing). RESULTS: The mean of the average air conduction hearing level of 124 ears was significantly improved from 34.7 to 27.1 dB after the final operation. Among them, 84 ears (67.8%) showed a hearing level of 30 dB or less post-operatively. Post-operative hearing was better in the one-stage group than in the staged group. However, more than one-half of the ears which underwent type IV tympanoplasty in the staged group showed post-operative air conduction hearing level of < or =30 dB. Significant improvement in post-operative hearing was noted in ears with normal middle ear mucosa or middle ear effusion at the final operation. No correlation between hearing improvement and clinical factors such as age, type of cholesteatoma or presence of otitis media with effusion at the first operation was found. CONCLUSIONS: Children with middle ear cholesteatoma at the age of 10 years or younger exhibited good hearing post-operatively. Satisfactory hearing improvement is expected even in ears without the superstructure of the stapes if staged tympanoplasty is conducted. Canal wall reconstruction tympanoplasty for pediatric cholesteatoma was successful in terms of hearing results and the success was unrelated to various clinical factors.

Bone Conduction↗

The 5-year incidence and progression of hearing loss: the epidemiology of hearing loss study.

CONTEXT: Hearing impairment affects many older adults, but the incidence is unknown. OBJECTIVE: To determine the 5-year incidence and progression of hearing impairment. DESIGN: A longitudinal, population-based study of adults aged 48 to 92 years at baseline examination. Hearing sensitivity was measured twice, 5 years apart. SETTING: Testing was conducted at the Beaver Dam Community Hospital, Beaver Dam, Wis. PARTICIPANTS: A total of 1636 participants without hearing loss and 1085 participants with hearing loss at the baseline examination in 1993-1995 were reexamined in 1998-2000. MAIN OUTCOME MEASURES: The examinations included otoscopy, screening tympanometry, and tone air- and bone-conduction audiometry. Incidence of hearing impairment was defined as a pure-tone average (PTA) of thresholds at 500, 1000, 2000, and 4000 Hz (PTA 0.5, 1, 2, and 4 kHz) greater than 25 dB HL (hearing level) in either ear at follow-up among those without hearing loss at baseline. Progression was defined as a change of more than 5 dB in the PTA 0.5, 1, 2, and 4 kHz among those with hearing loss at baseline. RESULTS: The 5-year incidence of hearing impairment was 21%. More than half of those with hearing loss at baseline experienced a decline in hearing. Age was an important risk factor for both incidence and progression. Male sex, occupation, and education were associated with the incidence of hearing loss after adjusting for age. CONCLUSIONS: Older adults have a high risk of developing hearing loss. Among those with hearing loss, most experience further declines in hearing sensitivity over time. These data indicate that hearing impairment is an important public health problem and underscore the need for appropriate hearing screening and treatment.

Acoustic Impedance Tests↗

Auditory localization in the horizontal plane with single and double hearing protection.

INTRODUCTION: Although single hearing protection devices such as earplugs or earmuffs are known to degrade sound localization, little is known about localization accuracy in double-hearing-protection conditions where both earplugs and earmuffs are worn at the same time. METHODS: Listeners wearing earplugs, earmuffs, or a combination of earplugs and earmuffs were asked to localize short (250 ms) or long (continuous) pink noise signals originating from one of 24 loudspeaker locations in the horizontal plane. RESULTS: When single hearing protection was worn, localization was reasonably accurate in the left-right dimension even when the stimuli were short in duration. When double hearing protection was worn, however, left-right localization accuracy was poor even when the stimuli were on continuously. A second experiment showed that localization accuracy with double hearing protection varied substantially across different listeners, but that it varied only slightly across refittings of the same earplugs and earmuffs on the same listener. A third experiment showed that double hearing protection impaired localization in the left-right dimension much more for narrow-band sounds at frequencies above 500 Hz than it did for narrowband sounds at frequencies at or below 250 Hz. DISCUSSION: The severe disruptions in performance that occurred when earmuffs and earplugs were worn simultaneously suggest the influence of a mechanism such as bone conduction that does not normally interfere with localization when only a single hearing protection device is used.

Adult↗

Effects of acute negative middle ear pressure on hearing. New answers to old questions and a review of the literature.

The magnitude of hearing loss caused by negative middle ear pressure is a controversial issue. We present a clinical, prospective and controlled study on the effect of negative middle ear pressure on hearing in human ears. Sixty-two ears of patients undergoing uvulopalatopharyngoplasty were examined pre- and postoperatively. The test group consisted of 31 ears in which negative postoperative middle ear pressure ranging between -150 and -400 mmH2O had developed. The control group consisted of 31 ears in which no middle ear pressure change was recorded after the same operation. Bone conduction hearing loss up to 20 dB (with a mean of 11 dB) at 250 Hz, up to 25 dB (with a mean of 13.1 dB) at 500 Hz and up to 10 dB (with a mean of 7.6) at 1,000 Hz was the dominant finding. An additional air-bone gap up to 15 dB (with a mean of 4.3 dB) was found only at 250 Hz. Basic theories about the acoustic response of the ear are discussed and new theories proposed.

Adult↗

Use of hydrogen peroxide to clear blocked ventilation tubes.

Blocked tympanostomy tubes re-create the problem for which they were initially inserted. Hydrogen peroxide offers a noninvasive alternative to extracting the blocked tube and inserting a new tube. In this article we present the results of a long-term retrospective study of 95 patients (113 ears) who had occluded ventilation tubes following myringotomy. An 85% rate of success in opening the clogged tube with hydrogen peroxide is documented. The ototoxicity of the treatment is also examined. Ninety-nine percent of the patients showed no immediate change in bone conduction thresholds following the use of hydrogen peroxide. We have concluded that hydrogen peroxide is a convenient, noninvasive, and inexpensive treatment for blocked ventilation tubes.

Bone Conduction↗

Seismic sensitivity in the desert golden mole (Eremitalpa granti): a review.

Behavioral and anatomical studies relating to possible seismic sensitivity in the desert golden mole (Eremitalpa granti) are reviewed. Field studies in the Namib desert have shown that isolated hummocks of dune grass generate low-frequency vibrations, distinct from the background noise at a distance of many meters. The golden mole apparently uses these cues to orient itself toward the hummocks and the prey species within. An analysis of middle ear morphology suggests that the massive malleus of the golden mole is adapted toward a form of inertial bone conduction, suitable for the detection of seismic cues obtained in this manner. The significance of seismic sensitivity in this golden mole is briefly discussed.

Animal Communication↗

The masking dilemma and its solution. Fusion at the inferred threshold (FIT) and sensorineural acuity level (SAL) tests.

It is difficult or impossible to obtain air or bone conduction threshold levels in some cases of moderately severe conductive involvement because it may be impossible to mask the nontest ear without also masking the test ear. This has been termed the "masking dilemma." In most of these "masking dilemma" cases the fusion at the inferred threshold (FIT) test can determine the air conduction hearing levels, and in some cases the sensorineural acuity level (SAL) test can help determine the sensorineural function.

Adolescent↗