Quantification of hearing loss associated with superior semi-circular canal dehiscence

Introduction

Superior semi-circular canal dehiscence (SSCD) is a known cause of hearing loss. This study quantifies hearing loss in SSCD ears in a frequency-specific fashion.

Methods

A meta-analysis of English language literature pertaining to SSCD was performed, with extraction and evaluation of available human audiometric data. Our own institution's case series of SSCD patients was also similarly analysed. Hearing loss in SSCD ears was compared to same patient control ears and to age-matched normative audiometric data.

Results

Ears with SSCD had statistically significant worse hearing as compared to both normative data and to own normal ear controls at 2000 Hz and below. The effect appears to diminish with increasing frequency.

Discussion

The presence of statistically significant conductive hearing loss in the low frequencies was confirmed for SSCD ears. SSCD may also predispose ears to high frequency sensorineural hearing loss.     

Earigate™ for softening ear wax: Is it safe when the eardrum is perforated?

Objective

To determine the safety of Earigate™ as an ear wax softening product.

Study Design

Prospective, controlled animal study.

Methods

Bilateral wide myringotomies were performed in eleven chinchillas. In each animal, Earigate™ was delivered to a randomly selected experimental ear canal as 2 puffs twice a day. Auditory brainstem response (ABR) was used to assess the hearing of the animals before, 3 days and 10 days following the local application of Earigate™. The ABR threshold shifts were compared for both experimental and control ears.

Results

The mean hearing threshold shifts in the experimental animals were comparable at all frequencies and at days 3 and 10. No statistically significant differences were observed in the mean threshold shifts for all of the frequencies evaluated, between the control and experimental ears.

Conclusions

The administration of Earigate™ to the middle ear of chinchillas did not cause any ototoxicity as assessed by ABR.     

A middle ear implant with a titanium canal wall prosthesis for a case of an open mastoid cavity

Objective

Open mastoid cavity rehabilitation should focus on both anatomical and functional aspects. We hereby report the technique and results of a combined strategy to reconstruct the external ear canal using a titanium wall implant and the middle ear using a fully implantable active middle ear device.

Methods

A fully implantable active middle ear implant was used to rehabilitate the mixed hearing loss of a 63-year-old woman, and a titanium posterior canal wall prosthesis was used to reconstruct the external ear canal during the same procedure. The middle ear implant was placed directly on the footplate. The auditory results were compared to the preoperative unaided thresholds and to the amplification of a conventional hearing aid.

Results

Following the procedure, there was an anatomically normal external ear canal with a healed tympanic membrane separating the external from the middle ear spaces. The postoperative auditory gains were on average 31.8 dB on pure-tone audiometry, and 20 dB on speech reception threshold. No complications occurred.

Conclusion

The rehabilitation of the external ear canal in an open mastoid cavity allows for clinical follow-up of the patient, and the implantation of an active middle ear implant provides appropriate auditory gains both in pure tones and in speech reception thresholds.     

Ocena niedosłuchu u osób powyżej 60. roku życia korzystających z aparatów słuchowych

Objective

To assess the hearing impairment in people over 60 years old using hearing aids. This was a single-center study, but it is planned to extend it further to the whole country.

Materials and methods

The study was focused on patients with hearing aids. During the assessment 57 people were included in the observation in order to control the status of their hearing loss and benefit from traditional hearing aids as well as the possibility to apply the auditory implants in case of a little benefit from hearing aids. The otoscopy and pure tone audiometry were performed as well as the questionnaires on demographic and epidemiological data of patients were collected as well as the quality of their life with hearing aids was subjectively assessed.

Results

The results show that 91% of patients have sensorineural hearing loss (SHL), the remaining 9% – severe mixed hearing loss. Severe SHL was found in 22 patients, the moderate hearing loss was observed in 37%, and the profound SHL was the case in 5 patients. Minimal SHL was observed in 7% of patients (n = 4). More than 73% of the study subjects were male (n = 38). The average age of the patients who completed the survey was 74 years old. Thirty-five patients used their hearing aid over 3 years and less than 70% of them used it every day all day. Hearing aid was not actively used by 10 patients. Over the last year 51.92% of the patients underwent a hearing examination.

Conclusions

The bone anchored hearing aid was suggested to 2% of subjects and the cochlear implant was offered to 10 patients. The data analysis shows the need to educate and inform the elderly about alternative methods of hearing loss treatment.     

Middle ear impedance measurements in large vestibular aqueduct syndrome

Objective

To assess the effect of inner ear pressure on middle ear impedance in patients with large vestibular aqueduct syndrome (LVAS).

Methods

Data from admittance tympanometry and multifrequency tympanometry on 8 LVAS patients and control subjects were studied.

Results

Static acoustic compliance (SAC) values for the ears with stable sensorineural hearing loss (SNHL) were within the limits of the mean values of control groups except for two ears. The resonance frequency (RF) values of the ears with stable SNHL were lower than the mean values of control groups except for three ears. SAC values for the two ears with fluctuating SNHL were lower and the RF values were higher than the mean values of control groups.

Conclusion

Decreased SAC values and increased RF values found in the ears with fluctuating SNHL might be an indirect indicator of increased inner ear pressure, while low RF values in the ears with stable SNHL might reflect the decreased inner ear impedance.     

Computed tomography demonstrates abnormalities of contralateral ear in subjects with unilateral sensorineural hearing loss

Purpose

Prior studies have associated gross inner ear abnormalities with pediatric sensorineural hearing loss (SNHL) using computed tomography (CT). No studies to date have specifically investigated morphologic inner ear abnormalities involving the contralateral unaffected ear in patients with unilateral SNHL. The purpose of this study is to evaluate contralateral inner ear structures of subjects with unilateral SNHL but no grossly abnormal findings on CT.

Materials and methods

IRB-approved retrospective analysis of pediatric temporal bone CT scans. 97 temporal bone CT scans, previously interpreted as “normal” based upon previously accepted guidelines by board certified neuroradiologists, were assessed using 12 measurements of the semicircular canals, cochlea and vestibule. The control-group consisted of 72 “normal” temporal bone CTs with underlying SNHL in the subject excluded. The study-group consisted of 25 normal-hearing contralateral temporal bones in subjects with unilateral SNHL. Multivariate analysis of covariance (MANCOVA) was then conducted to evaluate for differences between the study and control group.

Results

Cochlea basal turn lumen width was significantly greater in magnitude and central lucency of the lateral semicircular canal bony island was significantly lower in density for audiometrically normal ears of subjects with unilateral SNHL compared to controls.

Conclusion

Abnormalities of the inner ear were present in the contralateral audiometrically normal ears of subjects with unilateral SNHL. These data suggest that patients with unilateral SNHL may have a more pervasive disease process that results in abnormalities of both ears. The findings of a cochlea basal turn lumen width disparity >5% from “normal” and/or a lateral semicircular canal bony island central lucency disparity of >5% from “normal” may indicate inherent risk to the contralateral unaffected ear in pediatric patients with unilateral sensorineural hearing loss.     

Effect of nasal mometasone furoate on the nasal and nasopharyngeal flora

Objective

Mometasone furoate (MF) is one of the commonly used topical steroids, particularly for patients with allergic rhinitis. However, its effect on the colonization of bacteria that may cause superinfections by suppressing the local immunity is not known. Thus, we investigated the effect of MF use on the nasal and nasopharyngeal microbial flora.

Materials and methods

Swab samples were taken from 35 patients who required MF monotherapy, just before and after one month of the treatment. Samples were maintained in Stuart's medium. Each swab was transferred to 1 ml of a sterile saline solution, then into the standard agar. After incubation under 5% carbon dioxide at 37 °C, colony number was detected per ml.

Results

Colony counts of nasal or nasopharyngeal microbial flora did not show any statistically significant alteration with one month use of MF. However, an increase in potential pathogens as well as normal flora bacteria was determined in five of the patients and six patients acquired new nasopharyngeal potential pathogens, mostly Moraxella catarrhalis, Pseudomonas aeruginosa and Staphylococcus aureus, following the use of MF.

Conclusion

The use of MF for one month did not statistically significantly change the nasal and nasopharyngeal flora. This study indicates that MF could be increase the colonization of the potential pathogens in some of the patients at the subclinical level particularly in the nasopharyngeal area.     

Canal wall reconstruction and preservation in the surgical management of cholesteatoma in children with Down's syndrome

Introduction

Down's syndrome is associated with poor Eustachian tube function, and an increased incidence of cholesteatoma. The only previously published case series suggests that ‘canal wall preserving’ procedures are only rarely suitable for the management of cholesteatoma in this population.

Methods

We conducted a retrospective review of the hospital's clinical records database to identify patients with Down's syndrome and cholesteatoma. These patients’ notes were then reviewed.

Results

We identified nine patients with Down's syndrome who had undergone surgical management of cholesteatoma over a twelve year period. Three patients had bilateral disease, meaning twelve ears were treated. Seven ears were initially treated with ‘canal wall down’ procedures. Four out of five of the remaining ears were successfully treated using ‘canal wall preservation’ or ‘canal wall reconstruction’, with one ear requiring subsequent conversion to a ‘canal wall down’ approach.

Conclusion

Canal wall preservation/reconstruction is feasible in patients with Down's syndrome, even when cholesteatoma extends into the mastoid.     

The effect of cleft palate repair technique on hearing outcomes in children

Objective

Otitis media with effusion causing conductive hearing loss is a problem for many children with cleft palate. This study examines the association between palate repair technique and hearing outcomes in children at 3 and 6 years post-repair.

Patients and methods

Retrospective chart review of patients with all types of cleft palate that were repaired between 2001 and 2006 at a tertiary children's hospital. Exclusion criteria included sensorineural hearing loss, ossicular chain abnormalities, and ear canal abnormalities. The primary outcome was pure tone average (PTA) from 0.5 kHz to 2 kHz.

Results

69 patients (138 ears) were analyzed. 30.4% of left ears and 31.9% of right ears had an abnormal (>20 dB) PTA at 3 years; at 6 years this significantly improved to 13.0% (p = 0.008) and 15.9% (p = 0.011). Double-reverse z-plasty was associated with the lowest median PTA of 10.0 dB (p = 0.046) at 6 years. There was no difference in median PTA between children with and without comorbid diagnoses (such as Pierre Robin Sequence, arthrogryposis) at either 3 years or 6 years (p = 0.075, p = 0.331). Multivariate model showed that extent of cleft influenced technique choice (p = 0.027), but only technique choice was associated with significant differences in PTA and only at 6 years post-repair.

Conclusion

The majority of children developed normal hearing by 6 years with palatoplasty and routine tube insertion. Double reverse z-plasty was associated with the best outcome, but is not ideal for hard palate clefts. Randomized controlled trials are needed to elucidate the relationship between technique, middle ear ventilation and time to recovery, irrespective of type of cleft.     

The application of direct current electrical stimulation of the ear and cervical spine kinesitherapy in tinnitus treatment

Objective

The aim of the study was to evaluate the effectiveness of electrical stimulations of the hearing organ in tinnitus treatment adapting the frequency of stimulation according to tinnitus frequency, to assess the influence of cervical spine kinesitherapy on tinnitus, as well as to evaluate hearing after electrical stimulations alone and together with cervical spine kinesitherapy.

Methods

The study comprised 80 tinnitus, sensorineural hearing loss patients (119 tinnitus ears) divided into two groups. In group I (n – 58 tinnitus ears) electrical stimulation of the hearing organ was performed, in group II (n – 61 tinnitus ears) electrical stimulation together with cervical spine kinesitherapy. Hydrotransmissive, selective electrical stimulations were conducted using direct, rectangular current. The passive electrode was placed on the forehead, the active – a silver probe – was immersed in the external ear canal in 0.9% saline solution. The treatment involved fifteen applications of electrical stimulations (each lasted for 4 min) administered three or four times a week (whole treatment lasted approximately 30 days). The evaluation of the results considered a case history (change from permanent to temporary tinnitus), questionnaires (the increase/decrease of the total points) and the audiometric evaluation of hearing level.

Results

Before the treatment, group I comprised 51 ears (87.93%) with permanent, and 7 ears (12.07%) with temporary tinnitus; group II – 55 ears (90.17%) with permanent and 6 ears (9.83%) with temporary tinnitus. After the treatment, in both groups the number of ears with permanent tinnitus decreased considerably obtaining the pauses or disappearing of tinnitus. Directly after the treatment, group I comprised 25 ears (43.11%) with permanent, and 10 ears (17.24%) with temporary tinnitus, in 23 ears (39.65%) tinnitus disappeared; group II – 33 ears (54.1%) with permanent and 11 ears (18.03%) with temporary tinnitus, in 17 ears (27.87%) tinnitus disappeared.Regarding questionnaires, improvement was observed in group I – in 43.11% of ears, in group II – 32.8%. In both groups audiometric improvement of hearing was recognized.

Conclusions

(1) Electrical stimulation of the hearing organ, with the application of current frequencies according to tinnitus frequencies (selective electrical stimulation), was an efficient method in severe tinnitus treatment. (2) Cervical spine kinesitherapy in the treatment of tinnitus, using electrical stimulation, did not have any supporting influence.     

Keratinic amyloidosis of the external auditory canal

Objective

We present a rare case of keratinic amyloidosis of the external auditory canal. This is only the seventh case reported of localized cutaneous amyloidosis of the external auditory canal with no systemic symptoms.

Patient

A 62-year-old man, who had complained of an itchy external auditory canal and left-side hearing loss, was referred to our hospital because of a bilateral external auditory canal mass.

Intervention

Biopsy of the external auditory canal mass suggested a diagnosis of amyloidosis. However, total systemic examination failed to identify any disease due to systemic amyloidosis. This led us to diagnose him with localized cutaneous amyloidosis of the external auditory canal.

Main outcome measure

We follow up periodically with systemic examination and local observation.

Results

Thirty months after the initial diagnosis, he remains in follow-up and has not shown any significant aggravation of the disease.

Conclusion

In previous cases, the chief complaints were itching sensations and pain in the external auditory canal as well as a sense of discomfort when wearing a hearing aid. This suggests that chronic stimulation and inflammation of the skin lining the external auditory canal induced amyloidosis.     

Classification of trace patterns of 226- and 1000-Hz tympanometry in healthy neonates

Objective

Accurate evaluation of middle ear function is a challenge especially in babies referred from newborn hearing screening programs. The aim was to assess the feasibility of tympanometry using 226- and 1000-Hz probe tones in neonates.

Methods

Hearing was evaluated by transient evoked otoacoustic emission (TEOAE) in 96 ears of healthy neonates in well-baby nursery. Babies with risk factors for hearing loss as identified in Joint Committee on Infant Hearing (JCIH, 1994) were excluded. Tympanograms recorded with 226 and 1000 Hz probe tones were analyzed and classified.

Results

Tympanograms were classified according to Method A (Jerger/Liden) and visual classification systems, Method B (adapted from Marchant et al.) and Method C (adapted from Kei et al.), without difficulty. In 72 ears with normal TEOAE, 226 Hz tympanograms were classified as normal in 72 ears in Methods A and B, and 16 ears in Method C. 1000 Hz tympanograms were normal in 68 ears in Method A, 72 ears in Method B and 68 ears in Method C. In 24 ears with abnormal TEOAE, 226 Hz tympanograms were interpreted as normal in most ears (23 ears in Method A, 24 ears in Method B), whereas 1000 Hz tympanograms were abnormal in 13 ears in Method A and 6 ears in Method B, possibly reflecting middle ear dysfunction.

Conclusion

In healthy neonates without risk factors for hearing loss, 1000 Hz tympanograms can be recorded and interpreted. A single-peaked tympanograms was most common in ears with normal TEOAE. In ears with abnormal TEOAE, tympanograms were classified as abnormal more frequently using 1000 Hz than 226 Hz. Implementation of tympanometry using 1000 Hz probe tone in newborn hearing screening programs may provide valuable information regarding middle ear dysfunction that may cause transient conductive hearing loss.     

Benefit of a new hearing device utilizing cartilage conduction

Objective

Our previous study demonstrated that sound was effectively transmitted by attaching a transducer to the aural cartilage even without fixation pressure. This new method for sound transmission was found by Hosoi in 2004, and was termed cartilage conduction (CC). CC can be utilized even in hearing-impaired patients who cannot use air-conduction hearing aids owing to continuous otorrhea or aural atresia. A prototype hearing aid employing CC was investigated in this study.

Methods

Four patients with conditions such as continuous otorrhea and acquired aural atresia after surgery participated in this study. The CC hearing aid was fitted, and its benefits were assessed by audiometric tests and interview.

Results

Thresholds and speech recognition scores improved in all subjects. However, in subjects with continuous otorrhea, it was difficult to obtain the gains according to the target gains owing to their severe hearing loss and the limitation of the output level. On the other hand, unexpectedly large gains were obtained below 2 kHz in the patient with acquired aural atresia. These large gains were probably caused by soft tissue filling the postoperative space. No subjects complained of pain associated with the attachment of the transducer, although such problems are usually observed for a bone-conduction (BC) hearing aid. This feature is considered one of the advantages of the CC hearing aid.

Conclusion

The results of the audiometric tests and interview suggest that the CC hearing aid has potential as a useful amplification device for hearing disability. Unfortunately, if the soft tissue pathway is not involved, the current device is insufficient for the patients with severe hearing loss. The improvement of the output level will lead to develop a reliable CC hearing aid as an alternative to BC hearing aids or bone anchored hearing aids.     

Acquired middle ear cholesteatoma in children with cleft palate: Experience from 18 surgical cases

Objectives

To review an institutional experience with the surgical management of middle ear cholesteatoma in children with cleft palate.

Materials and methods

We analyzed retrospectively 18 children diagnosed with cleft palate who underwent surgery for acquired middle ear cholesteatoma between 2000 and 2007. The following data were recorded: age, sex, history of ventilation tube insertion, status of the contralateral ear, cholesteatoma location and extension, and surgical technique involved. Cholesteatoma recidivism, stable mastoid cavity and hearing levels were the main outcomes measured.

Results

Follow-up ranged from 5 to 12 years (mean 8 years). Twelve children underwent planned staged canal wall up mastoidectomy: a residual cholesteatoma was found and removed during the second-look procedure in 2 ears (16.6%); two children (16.6%) showed a recurrent cholesteatoma and required conversion to canal wall down mastoidectomy. A modified Bondy technique was chosen in two children with an epitympanic cholesteatoma with an intact tympano-ossicular system, while in the remaining four subjects a canal wall down mastoidectomy was performed because of an irreparable erosion of the postero-superior canal wall: no cases of recurrent cholesteatoma were observed in these 6 children; revision mastoidectomy was needed in one patient for cavity granulation. A postoperative air-bone gap result of 0–20 dB was achieved in 11 children (61.1%); in 5 cases (27.7%) postoperative air-bone gap was between 21 and 30 dB, while in 2 (11.1%) was >30 dB. Bone conduction thresholds remained unaffected in all cases.

Conclusions

Our results indicate that most cleft palate children with cholesteatoma can be managed with a canal wall up mastoidectomy with low complication rates. In extensive disease with large erosion of the canal wall as well in presence of a retraction pocket in the contralateral ear, a canal wall down mastoidectomy should be considered. In epitympanic cholesteatomas with an intact tympano-ossicular system and mesotympanum free of disease, the modified Bondy procedure is an effective surgical option. As in the general pediatric population, improvement or preservation of hearing can be obtained in most patients.     

Evaluation of tinnitus patients with normal hearing sensitivity using TEOAEs and TEN test

Objectives

This study was designed to investigate the possibility of underlying cochlear damage whether outer hair cells (OHCs) or inner hair cells (IHCs) in tinnitus suffering patients with normal hearing sensitivity, using transient evoked otoacoustic emission (TEOAEs) and threshold equalizing noise (TEN) test, if any.

Methods

Twenty patients suffering from unilateral tinnitus with normal hearing sensitivity participated in this study. Their other ear acted as control ears. They were subjected to full history taking, otoscopy, basic audiologic evaluation, TEOAEs and TEN test.

Results

TEOAEs were abnormal in 85% of the tinnitus ears compared to 20% in control ears; this difference was statistically significant. The abnormal TEOAEs frequency bands in the tinnitus ears were statistically significant above 2000 Hz when compared to the control ears and were more common for the 4000 and 5000 Hz. This suggests that OHCs dysfunction may be important in the generation of tinnitus. TEN test demonstrated dead regions in the cochlea in 15% of the tinnitus ears only. This might be attributed to increased resistance of IHCs to damage compared to OHCs vulnerability. The affected frequency location was at 500 Hz in 5%, 3000 and 4000 Hz in 10% of tinnitus ears.

Conclusion

This work has shown a higher prevalence of OAE abnormalities in tinnitus patients with normal hearing in contrast to TEN test denoting the more vulnerability of OHCs to damage.     

Middle ear metastasis of thymoma

Objective

We report an extremely rare case of thymoma which developed middle ear metastasis along with acute sensorineural hearing loss in the contra ear.

Method

We present a case report and a review of the world literature concerning thymoma metastases to the middle ear.

Results

A 54-year-old female patient with thymoma who developed middle ear metastasis along with acute sensorineural hearing loss in the contra ear.

Conclusion

We have not found out thymoma metastases to the middle ear in the past.     

Aided cortical response,speech intelligibility,consonant perception and functional performance of young children using conventional amplification or nonlinear frequency compression

Objective

The aim of this study was to compare conventional processing with nonlinear frequency compression (NLFC) in hearing aids for young children with bilateral hearing loss.

Methods

Sixty-four children aged between 2 and 7 years with bilateral hearing aids were recruited. Evaluations of cortical responses, speech intelligibility rating, consonant perception and functional performance were completed with the children wearing their personal hearing aids with conventional processing. The children were then refitted with new hearing aids with NLFC processing. Following a six-week familiarization period, they were evaluated again while using their hearing aids with NLFC activated.

Results

The mean speech intelligibility rating and the number of cortical responses present for /s/were significantly higher when children were using NLFC processing than conventional processing in their hearing aids (p < 0.05). Parents judged the children's functional real life performance with the NLFC hearing aids to be similar or better than that with the children's own hearing aids in both quiet and noisy situations. The mean percent consonant score was higher with NLFC processing compared to conventional processing, but the difference did not reach the 5% significance level (p = 0.056). An overall figure of merit (FOM) was calculated by averaging the standardized difference scores between processing schemes for all measures. Regression analysis revealed that, on average, greater advantage for NLFC processing was associated with poorer hearing at 4 kHz.

Conclusions

Compared to conventional processing, the use of NLFC was, on average, effective in increasing audibility of /s/as measured by cortical evaluations, and higher ratings on speech intelligibility and functional performance in real life by parents. On average, greater benefits from NLFC processing was associated with poorer hearing at 4 kHz.     

Is sensorineural hearing loss with chronic otitis media due to infection or aging in older patients?

Objective

To clarify true incidence of sensorineural hearing loss in ears with chronic otitis media (COM).

Methods

Bone conduction (BC) hearing thresholds of 180 preoperative patients (207 ears) with COM and 226 normal individuals (289 ears) were measured by audiometry, and the percentage of ears with BC thresholds being higher than normal range was evaluated in the COM group. In the COM group, the size of the perforation on the eardrum (n = 196) and the cross-sectional area of the mastoid air cells based on the axial CT image (n = 103) were also measured and correlated with the results of BC threshold.

Results

The percentage of ears with BC thresholds being higher than normal range calculated from comparison to the control group tended to increase with age, ranging from 4.5% in the 20s to 34.1% in the 60s with an average of 26.6%. The increase in the BC thresholds did not correlate with the size of eardrum perforation, but correlated well with the size of the mastoid air cells.

Conclusion

These results may suggest that all measures for early cure, including surgery, should be considered as early as possible for patients with COM.     

Hearing threshold assessment in young children with electrocochleograpy (EcochG) and auditory brainstem responses (ABR): Experience at the University Hospital of Ferrara

Objective

Electrophysiological evaluation is a fundamental procedure for the diagnostic assessment of hearing loss during infancy; in these cases, information concerning threshold level and auditory perception is particularly useful to establish a correct hearing rehabilitation program (hearing aids and cochlear implants).Purpose of this study is to underline the role of auditory brainstem responses (ABR) and electrocochleography (EcochG) in the definition of hearing loss in a selected group of children, referred to the Audiology Department of the University Hospital of Ferrara, for a tertiary level audiological assessment.

Methods

A retrospective study of the paediatric patient database at the Audiology Department of the University Hospital of Ferrara has been performed. In a period between January 2000 and December 2007, a total of 272 paediatric cases have been identified (544 ears).An EM 12 Mercury apparatus has been used for the electrophysiological threshold identification (ABR and EcochG). Recordings were carried out under general anaesthesia, in a protected enviroment.

Results

In 19 of the 272 paediatric cases selected—38 ears (7%), the results of threshold evaluation through ABR were uncertain. The Ecochg recording resulted crucial for the final diagnosis in terms of definition of the hearing threshold level, and it was then possible to ensure the better hearing rehabilitation strategy.

Conclusions

ABR has to be considered the first choice in hearing assessment strategy, either for screening or for diagnosis in newborns as well as in non-collaborating children; ECochG still may be considered a reliable diagnostic tool.     

Tone burst stimulus for auditory brainstem responses: Prediction of hearing threshold at 1 kHz

Objective

To assess differences in hearing threshold estimation of four different ABR tone-bursts at 1 kHz.

Methods

Twenty-one (21) ears from 11 subjects were tested with pure-tone audiometry (PTA): 5 ears (24%) were normal hearing, 5 (24%) affected by mild hearing loss, 7 (33%) showed moderate hearing loss and 4 (19%) severe hearing loss. After PTA each subject underwent tone-burst ABR test at 1 kHz using a linear gated (L_ABR) or Blackman windowed (B_ABR) stimuli with (nn_ABR) and without ipsilateral notched noise. Stimulation rate and filters settings were unchanged.

Results

Overall correlation between PTA and all ABRs thresholds was high, ranging from 0.84 to 0.94. In normal hearing ears none of the differences was significant, except for those measured with B_nn_ABR, which showed a mean 16 dB overestimation of the pure-tone threshold (p < 0.05). In mild hearing loss group none of the differences between thresholds were significant. In moderate and severe hearing loss groups significant differences were measured with L_nn_ABR (p < 0.05) with a mean 7.5 dB underestimation of PTA.

Conclusions

Although very similar, some significant differences were found when considering specific group of patients with different degrees of hearing loss.