Deterioration Of Hearing Thresholds Research Articles

A longitudinal community-based ototoxicity monitoring programme and treatment effects for drug-resistant tuberculosis treatment, Western Cape.

BackgroundSouth Africa has a high burden of drug-resistant tuberculosis (DRTB) and until recently, ototoxic aminoglycosides were predominant in treatment regimens. Community-based ototoxicity monitoring programmes (OMPs) have been implemented for early detection of hearing loss and increased patient access.ObjectivesA longitudinal study was conducted to describe the service delivery characteristics of a community-based OMP for DRTB patients facilitated by CHWs as well as observed ototoxic hearing loss in this population.MethodA descriptive retrospective record review of longitudinal ototoxicity monitoring of 194 DRTB patients undergoing treatment at community-based clinics in the city of Cape Town between 2013 and 2017.ResultsFollow-up rates between consecutive monitoring assessments reached as high as 80.6% for patients assessed by CHWs. Few patients (14.2% – 32.6%) were assessed with the regularity (≥ 6 assessments) and frequency required for effective ototoxicity monitoring, with assessments conducted, on average, every 53.4–64.3 days. Following DRTB treatment, 51.5% of patients presented with a significant ototoxic shift meeting one or more of the American Speech-Language-Hearing Association (ASHA) criteria. Deterioration in hearing thresholds was bilateral and most pronounced at high frequencies (4 kHz – 8 kHz). The presence of pre-existing hearing loss, human immunodeficiency virus co-infection and a history of noise exposure were significant predictors of ototoxicity in patients.ConclusionDRTB treatment with kanamycin resulted in significant deterioration of hearing longitudinally, predominantly at high frequencies. With ongoing training and supportive supervision, CHWs can facilitate community-based ototoxicity monitoring of DRTB patients. Current protocols and guidelines may require reassessment for appropriate community-based ototoxicity monitoring.

Feasibility and first results of a prospective cohort study to investigate cisplatin-associated ototoxicity amongst cancer patients in South Africa

BackgroundCervical cancer, one of the most common cancers affecting females in South Africa, commonly requires a cisplatin-based-treatment regimen, which has been associated with ototoxic side effects. However, cisplatin-associated ototoxicity is largely under-reported in South Africa, despite its impact of hearing loss having serious overt ramifications on the quality of life of these patients. Hence, a prospective cohort study was undertaken to assess the audiological changes in female cervical cancer patients receiving cisplatin therapy.ObjectiveTo present details of the feasibility study and initial results on hearing patterns in cervical cancer patients receiving cisplatin chemotherapy. .MethodsFifty cervical cancer patients commencing with cisplatin chemotherapy underwent audiological assessments at a hospital in South Africa at various time intervals. Assessments included case history, otoscopic examination, immittance audiometry, pure tone audiometry (including high-frequency audiometry), speech audiometry, and distortion product otoacoustic emission testing. Data analysis involved the use of descriptive statistics and the Cochran-Armitage trend test for a linear trend in proportions.ResultsFifty participants, aged between 32 and 79 years (Mean: 53 years; SD = 11.00), were recruited. Clinical findings revealed an incidence of 100% ototoxic hearing loss at the one-month post-treatment, i.e., 98% after three cycles of cisplatin and 2% at one-month post-chemotherapy. Sensorineural hearing loss and high-frequency tinnitus were most common. Deterioration in hearing thresholds was more evident in the extended high-frequency range, with the number of “no-responses,” from 11,200 Hz to 20,000 Hz, increasing with each successive audiological evaluation. This study further indicated that recruitment and follow-up of study participants within a limited resource setting are possible. However, cognizance must be given to a multidisciplinary approach and constant engagement with participants through regular contact either telephonically or via a short-message-system.ConclusionExposure to cisplatin treatment contributed to hearing loss in females with cervical cancer, highlighting the need for ototoxicity monitoring during chemotherapy treatments. Furthermore, the results indicate that it is possible to conduct prospective cohort studies, using a multidisciplinary approach in limited-resource environments with appropriate planning and training strategies, as this study was able to achieve its aim successfully.

The Clinical Effects of Steroids Therapy in the Preserving Residual Hearing after Cochlear Implantation with the OTICON Neuro Zti EVO.

Background: A prospective clinical study was conducted to investigate whether two different pharmacotherapy strategies of steroid administration impact hearing preservation in adult patients who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system. Methods: Twenty nine adult participants were included. Pure tone audiometry was performed before implantation, during processor activation and 12 months after activation. There were three treatment groups: (1) intravenous steroid therapy (standard steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg body mass twice a day); (2) combined oral and intravenous steroid therapy (extended steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg b.m. twice a day and prednisone (orally) at the dose 1 mg/kg body mass/24 h), and (3) no steroid therapy (a control group). Patients’ hearing thresholds before implantation were on average 103 dB HL, 89 dB HL, and 93 dB HL, respectively. Results: Deterioration of hearing thresholds was observed in all three patients’ groups. Twelve months after surgery the patients with and without steroid therapy had similar hearing thresholds. Conclusions: The steroid regimen used in this study did not play a significant role in patients with non-functional residual hearing, who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system.

A common variant in CLDN14 causes precipitous, prelingual sensorineural hearing loss in multiple families due to founder effect

Genetic isolates provide unprecedented opportunities to identify pathogenic mutations and explore the full natural history of clinically heterogeneous phenotypes such as hearing loss. We noticed a unique audioprofile, characterized by prelingual and rapid deterioration of hearing thresholds at frequencies >0.5 kHz in several adults from unrelated families from the island population of Newfoundland. Targeted serial Sanger sequencing of probands for deafness alleles (n = 23) that we previously identified in this founder population was negative. Whole exome sequencing in four members of the largest family (R2010) identified a CLDN14 (DFNB29) variant [c.488C>T; p. (Ala163Val)], likely pathogenic, sensorineural hearing loss, autosomal recessive. Although not associated with deafness or disease, CLDN14 p.(Ala163Val) has been previously reported as a variant of uncertain significance (VUS). Targeted sequencing of 169 deafness probands identified one homozygote and one heterozygous carrier. Genealogical studies, cascade sequencing and haplotype analysis across four unrelated families showed all subjects with the unique audioprofile (n = 12) were also homozygous for p.(Ala163Val) and shared a 1.4 Mb DFNB29-associated haplotype on chromosome 21. Most significantly, sequencing 175 population controls revealed 1% of the population are heterozygous for CLDN14 p.(Ala163Val), consistent with a major founder effect in Newfoundland. The youngest CLDN14 [c.488C>T; p.(Ala163Val)] homozygote passed newborn screening and had normal hearing thresholds up to 3 years of age, which then deteriorated to a precipitous loss >1 kHz during the first decade. Our study suggests that genetic testing may be necessary to identify at-risk children in time to prevent speech, language and developmental delay.

Progressive Hearing Loss in Early Childhood.

Deterioration in hearing thresholds in children is of concern due to the effect on language development. Before universal newborn hearing screening (UNHS), accurate information on the progression of hearing loss was difficult to obtain due to limited information on hearing loss onset. The objective of this population-based study was to document the proportion of children who experienced progressive loss in a cohort followed through a UNHS program in one region of Canada. We explored risk factors for progression including risk indicators, audiologic, and clinical characteristics of children. We also investigated deterioration in hearing as a function of age. For this study, two working definitions of progressive hearing loss were adopted: (1) a change of ≥20 dB in the 3 frequencies (500, 1000, and 2000 Hz) pure-tone average, and (2) a decrease of ≥10 dB at two or more adjacent frequencies between 500 and 4000 Hz or a decrease in 15 dB at one octave frequency in the same frequency range. Population-based data were collected prospectively on a cohort of children identified from 2003 to 2013 after the implementation of UNHS. Clinical characteristics including risk indicators (as per Joint Committee on Infant Hearing), age at diagnosis, type and severity of hearing loss, and initial audiologic information were recorded when children were first identified with hearing loss. Serial audiometric results were extracted from the medical charts for this study. Differences between children with progressive and stable hearing loss were explored using χ tests. Association between risk indicators and progressive hearing loss was assessed through logistic regression. The cumulative amount of deterioration in hearing from 1 to 4 years of age was also examined. Our analysis of 330 children (251 exposed to screening) with detailed audiologic records showed that 158 (47.9%) children had some deterioration (at least ≥10 dB and) in hearing thresholds in at least one ear. The 158 children included 76 (48.1%) with ≥20 dB loss in pure-tone average in at least one ear and 82 (51.9%) with less deterioration in hearing levels (≥10 but <20 dB). In the children with progressive hearing loss, of 131 children initially diagnosed with bilateral loss, 75 (57.3%) experienced deterioration in 1 ear and 56 (112 ears; 42.7%) in both ears (total of 187 ears). Of 27 children with an initial diagnosis of unilateral loss, 25 experienced deterioration in the impaired ear and 5 in the normal-hearing ear, progressing to bilateral hearing loss. Within 4 years after diagnosis, the mean decrease in hearing for children with progressive loss was 25.9 dB (SD: 16.4) in the right ear and 28.3 dB (SD: 12.9) in the left ear. We explored the risk factors for hearing loss identified by Joint Committee on Infant Hearing where there were sufficient numbers in our sample. On multivariate analysis, there was no statistically significant relationship between most risk indicators examined (neonatal intensive care unit admission, family history, syndromes, and postnatal infections) and the likelihood of progressive loss. However, the presence of craniofacial anomalies was inversely associated with risk of progressive hearing loss (odds ratio = 0.27; 95% confidence interval: 0.10, 0.71; p = 0.01), that is, these children were more likely to have stable hearing. Given that almost half of the children in this cohort experienced deterioration in hearing, close postneonatal monitoring of hearing following early hearing loss identification is essential to ensure optimal amplification and therapy.

Effectiveness of medical interventions implemented during ototoxicity monitoring to prevent further deterioration of hearing thresholds

Background: MDR-TB patients are often treated with aminoglycosides which may lead to irreversible ototoxic hearing impairment. Early identification of changes in the hearing thresholds of patient is critical in facilitating treatment modifications that can minimise communication impairment.Design: A retrospective review of medical records of all patients who underwent ototoxicity monitoring from 2012-2014 was conducted. Patients treated with aminoglycosides and with normal hearing thresholds at baseline were included.Results: 26 of 509 patient records met inclusion criteria. There were 9 males and 17 females. The mean age was 36.81±11.48. Half of the participants were on treatment for ≤160 days, whereas the rest were on treatment for ≥161 days. The greatest deterioration in hearing thresholds (post-treatment initiation) occurred in the high frequencies (4-8 kHz). Participants on treatment for >160 days had the greatest deterioration in hearing thresholds. Modifying the frequency of drug administration led to a lesser degree of deterioration of hearing thresholds.Conclusion: Early detection of deterioration in hearing thresholds can potentially minimise ototoxicity in patients who are being treated with aminoglycosides. More research is needed regarding the effectiveness of these strategies.

The occurrence of tinnitus after CI surgery in patients with severe hearing loss: A retrospective study

Objective: An often reported side-effect of a cochlear implant (CI) is suppression of tinnitus. However, induction of tinnitus is also a known complication of CI surgery. To date, it remains unclear why some CI recipients experience larger tinnitus complaints due to CI surgery while most others do not. The goal of this study was to investigate the effect of deterioration of residual hearing due to CI surgery on tinnitus. Design: In this retrospective database study, pre- and postoperative audiometric hearing thresholds were retrieved from patients’ clinical files. Furthermore, tinnitus questionnaires were sent to all patients who fitted inclusion criteria. Study sample: Of the 512 CI patients who were implanted within the last ten years, 197 patients fitted the inclusion criteria and returned the questionnaires. Results: We identified 39 cases (19.8%) who suffered from a newly developed (25) or deteriorated (14) tinnitus following CI surgery. No statistically significant association between perioperative deterioration of hearing thresholds measured by pure-tone audiometry and the development or deterioration of tinnitus was found. Conclusions: There is a small risk for deteriorated residual hearing after cochlear implantation. However, for patients with preoperative residual hearing, there appears to be no increased risk of developing chronic tinnitus after hearing deterioration due to cochlear implantation.

Hearing preservation and improved speech perception with a flexible 28-mm electrode.

The present study aimed to determine the extent of hearing preservation retrospectively after atraumatic cochlear implant (CI) surgery using a specialized surgical technique and specially designed flexible electrode to minimize cochlear trauma. Retrospective study. Academic tertiary care center. A consecutive series of 34 patients who had some preoperative residual hearing were included in this study. Patients underwent CI surgery with a flexible 28-mm electrode using a round window insertion technique. All patients had at least 6 months of postoperative follow-up including audiometric testing and speech perception determined using the Freiburg monosyllable word test and the Oldenburger Sentence Test in noise. Audiometric testing served as a proxy for the evaluation of cochlear trauma and hearing preservation. Hearing was preserved to within 20 dB of preoperative low-frequency pure-tone audiometry (PTA) in 40.7% of patients. Hearing was preserved to within 20 dB of preoperative high-frequency PTA in 35.7% of patients. Overall, a deterioration in hearing thresholds was observed between preoperative assessment and first fitting. Speech perception improved significantly over time after surgery. Using appropriate surgical techniques, and electrodes specially designed to minimize cochlear trauma, hearing preservation can be achieved.

Mild Bilateral and Unilateral Hearing Loss in Childhood

There is some evidence that the presence of even mild degrees of hearing loss and unilateral loss in early childhood can negatively affect typical development. Consequently, the identification of all children with permanent hearing loss including those with milder degrees of hearing loss is currently targeted through some newborn hearing screening initiatives. The objectives of this study were to document the proportion of children identified with mild bilateral or unilateral hearing loss (MBUHL) before and after the implementation of a universal newborn hearing screening program (UNHS). A second objective was to examine the clinical characteristics and audiologic management of this population of children. This population-based study involved an analysis of data on children with hearing loss; these data had been collected prospectively over a 20-year period from 1990 to 2010 in a publicly funded pediatric teaching hospital in Canada, which provided diagnostic audiology services for all children in the region. The proportion of all children with hearing loss identified with MBUHL before and after implementation of UNHS and their clinical profiles were documented. Data related to amplification use were also retrospectively extracted from detailed medical chart reviews to investigate clinical recommendations regarding amplification and subsequent use of hearing devices. Factors affecting amplification decisions and amplification use were examined. A total of 381 of 823 children (46.3%) aged 0 to 18 years who were identified with permanent nonacquired hearing loss presented with MBUHL. The proportions identified were similar in the pre- and post-UNHS periods (p = 0.207). Before UNHS children were identified at a median age of 5.0 years (interquartile range: 3.6 to 7.0) compared with a median of 0.8 years, (interquartile range: 0.3 to 2.3) post-UNHS. Progression of hearing loss was documented for 22% of all children, and for the group identified since UNHS, 32.4% experienced deterioration in hearing thresholds. Although 87.2 % of children received recommendations for amplification, more than 50% experienced considerable delay from identification to amplification. Age at identification and severity of hearing loss in the better ear were associated with amplification decisions for bilateral but not unilateral loss. MBUHL constitutes almost half of childhood hearing loss. UNHS has lowered age of confirmation of MBUHL by 4 to 5 years. Delay to amplification suggests uncertainty of the benefit of intervening early for these losses. Further research is required to determine the effects of early-identified MBUHL on children's development and to document the benefits of early amplification.

An “Uncrimped” SMart Stapes Prosthesis: A Cause of Late Hearing Deterioration in Otosclerosis

Statement of Problem. Stapedotomy is the treatment of choice for otosclerosis. Numerous techniques and prosthesis are available to perform this procedure. Success rates of surgery vary from 17% to 80%, and revision surgery carries an increased risk of complications as well as poorer hearing outcomes. Method of Study. Case report. Results. We report the first case of uncrimping of a SMart stapes prosthesis with no lateral displacement as a cause of late failure despite successful crimping and improvement in audiological outcomes after initial surgery. Conclusion. The SMart stapes prosthesis is widely used and has been shown to be safe and provide good hearing outcomes. Displacement of a stapes prosthesis is the commonest cause of failure. Our case shows that deterioration of hearing thresholds can occur from uncrimping of the prosthesis with no displacement. It is important to improve our understanding of stapedotomy failure as revision procedures are associated with poorer outcomes.

Long term hearing degeneration after platinum-based chemotherapy in childhood

The aim of this study was to investigate long-term development of hearing in subjects who had received platinum-based chemotherapy in childhood or adolescence. Another aim was to assess the self-reported hearing loss handicap and compare it to audiometric measurements. Medical records from individuals diagnosed with childhood cancer and treated with platinum-based chemotherapy between 1985 and 2000 at the University Hospital in Lund Sweden were reviewed retrospectively. Fifteen subjects, who fulfilled the eligibility criteria set for the study, underwent a thorough audiometric evaluation. The results show that the hearing loss, in subjects with ototoxicity had increased after the end of treatment, to include also the lower frequencies. The largest deterioration in hearing thresholds, up to 55 dB HL, was found at frequencies above 2 kHz. The findings also reveal that the subjects have a considerably greater hearing loss handicap and disability than would be expected from the results of the audiometric evaluations. The conclusion of this study is that children and adolescence treated with platinum-based chemotherapy should have regular audiometric follow-up examinations, also many years after the end of treatment. Furthermore, assessments of self-reported hearing disability should be made during and after chemotherapy.SumarioEl objetivo de este estudio fue investigar el desarrollo de la audición a largo plazo en sujetos que recibieron quimioterapia de platino en la niñez o en la adolescencia. Otro objetivo fue evaluar los auto-reportes de discapacidad por la pérdida auditiva y compararlos con las mediciones audiométricas. Se revisaron retrospectivamente los expedientes médicos de individuos diagnosticados con cáncer en la niñez y tratados con quimioterapia con platino entre 1985 y 2000, en el Hospital Universitario de Lund, Suecia. Quince sujetos que cubrieron los criterios de elegibilidad para el estudio, se sometieron a una evaluación audiométrica minuciosa. Los resultados mostraron que la pérdida auditiva en sujetos con ototoxicidad aumentó después de terminar el tratamiento, incluyendo también las frecuencias graves. La mayor pérdida en los umbrales auditivos, hasta de 55 dB HL, se encontró en las frecuencias superiores a 2 kHz. Los hallazgos revelan también que los sujetos presentan una discapacidad y una desventaja auditiva considerablemente mayor que lo que podría esperarse a partir de los resultados de las evaluaciones audiométricas. La conclusión de este estudio es que los niños y adolescentes tratados con quimioterapia con platino deben ser sometidos a un seguimiento en las evaluaciones audiométricas, incluso muchos años después de terminar el tratamiento. Más aún, las evaluaciones de los auto-reportes sobre discapacidad auditiva, deben practicarse durante y después de la quimioterapia.

Influence of Meniett® treatment on hearing

Conclusions: Meniett® treatment was not shown to avoid deterioration of hearing threshold in patients with Meniere's disease (MD), even when achieving a fairly good therapeutic outcome on vertigo control. Objectives: To describe the effect of Meniett® treatment on hearing threshold in patients with MD. Methods: From a cohort of 55 patients with diagnosis of definitive MD, who underwent Meniett® treatment over the last decade, 27 were selected for the present study as having at least 2 years from the end of treatment. They all received the treatment for 1 month and underwent hearing evaluation as pure tone average (PTA) from 500 to 4000 Hertz at the time of diagnosis, immediately before the treatment, immediately after the treatment, and at the end of the follow-up. Vertigo control was assessed by applying the 1995 AAO-HNS criteria as well as by administration of the Dizziness Handicap Inventory (DHI) questionnaire. Statistical analysis was carried out using paired t test, Wilcoxon signed-rank tests, and multiple linear regressions. Results: PTA values increased on average by 7.1 dB (95% CI = 2.7–11.5; p = 0.003) during the time period from the beginning of the treatment to the end of the follow-up. Q scores decreased on average by 20.6 (95% CI = 8.8–32.4; p < 0.001) during the pre- and post-Meniett® time-span. These two outcomes appeared not to influence each other.

Totally implantable middle ear device for rehabilitation of sensorineural hearing loss: preliminary experience with the Esteem®, Envoy

Conclusion. According to the first series of implanted patients, Esteem 2® technology can be regarded as a safe and reliable system for hearing restoration in case of moderate to severe sensorineural hearing loss. Objectives. To assess the benefit deriving from implantation of a totally implantable middle ear device in subjects affected by moderate to severe sensorineural hearing loss, the Esteem 2® (Envoy Medical), as measured through pure tone audiometry testing carried out during the different postoperative fitting sessions. Patients and methods. Six patients have been operated on since July 2007. Selection was carried out via preoperative audiometric tests and thorough counseling, which considered information on previous experience with conventional hearing aids as well as each patient's motivation to undergo a surgical application. Specific surgical training is needed to accommodate routine surgical steps along with less familiar steps, such as placement of cement material and overall fixation of the system. Results. The surgical procedure took a long time, but a reduced duration was recorded in the last procedure compared with the first one. The implantation process induced a deterioration in hearing thresholds, which fully recovered after activation of the device. A postoperative hearing gain could be measured in all three patients: in this regard, the perceived quality of sound was shown to be better than could be expected by the measurable hearing gain.

The Floating Mass Transducer of the Vibrant Soundbridge Interposed Between the Stapes and Tympanic Membrane After Incus Necrosis

The floating mass transducer (FMT) of the Vibrant Soundbridge (VSB) can be interposed in the middle ear in case of an absent incus. The VSB is a middle ear implant in which the FMT is attached to the long process of the incus to directly drive the ossicular chain. In this case report, there was gradual deterioration in speech perception after VSB fitting and deterioration in hearing thresholds. During exploratory resurgery, it became clear that the ossicular chain was interrupted due to necrosis of the long process of the incus. The VSB could no longer function because there was no connection between the incus and stapes. Reconnection of the FMT to the anterior crus of the stapes on 1 side and the tympanic membrane on the other side. Reconnection of the FMT to the stapes head led to obvious improvement in audiometric results. The air-bone gap was reduced from approximately 35 to approximately 25 dB, which indicated that the construction with the FMT was working like a partial ossicular replacement prosthesis. At 1.5 years' follow-up, the aided hearing thresholds of approximately 45 dB hearing level were slightly poorer than those measured after the first procedure with classical positioning of the FMT. However, the speech recognition score in quiet at 65 dB sound pressure level was 70% with the classical FMT application and with the FMT connected between the stapes and tympanic membrane. It could be concluded that when the incus is absent, placement of the FMT directly on to the stapes is an acceptable solution.

Acoustic neuroma surgery: the results of long-term hearing preservation.

To report the long-term outcome hearing results following acoustic neuroma surgery. To determine whether changes, if any, in the thresholds of the operated ear are mirrored in the contralateral unoperated side. In addition, to identify predictive factors, if any, that may predispose individuals to hearing loss in the operated ear in the late post-operative period. Retrospective patient chart review. University Tertiary Referral Centre. From 1978 to 1997, one hundred and twenty six patients with small acoustic neuromas (less than 2 cm as measured within in the cerebellopontine angle) underwent excision via the suboccipital (retrosigmoid) approach with the patient in the prone position. Hearing preservation was successful in 43 patients (34.1%). The audiometric data of thirty patients with a minimum follow-up interval of 36 months was analyzed. The mean follow-up period was 113.4 months (range 36-264, SD=57.8) and the mean age at surgery was 47.3 years (range 32 to 64, SD = 7.3). Speech Reception Thresholds (SRT), Speech Discrimination Scores (SDS) and Pure-tone Audiometry (PTA, 0.5, 1 & 2 kHz) were noted on the operated and unoperated ears. The AAO Classification according to the Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma was used to assess hearing serviceability. Subsequent to including corresponding changes in the unoperated ear, the means of the SRT and PTA in the operated ear between the early and late post-operative periods were statistically significantly different (p=0.0012 & 0.034 respectively). Twelve (40%) patients demonstrated significant deterioration in hearing thresholds over time. Pre-operatively, 96.7% of patients had serviceable hearing (Class A & B). This falls to 76.6% in the early post-operative period and to 56.7% in the late post-operative period. Our study highlights the finding that over time a significant number of individuals realize a greater ongoing hearing loss in the post tumour excision ear than the contralateral ear.

The effect of the ?floating mass transducer? in the middle ear on hearing sensitivity

The Vibrant soundbridge is a semi-implantable hearing device; the transducer is implanted, coupled directly to the incus. The influence of the implant surgery and the presence of the transducer on hearing sensitivity was studied in six implanted subjects.Longitudinal case reports.Tertiary referral center. Subjects. The subjects had bilateral sensorineural hearing loss with an average hearing loss of 40 to 70 dB HL.In five of the six subjects, no long-term effect of the surgery or the presence of the transducer on hearing thresholds was found. In the remaining subject, a deterioration in hearing thresholds was found of 20 dB, with a high and low frequency component. In the 2-kHz region, hearing sensitivity was not deteriorated. In addition, chronic negative middle ear pressure occurred after surgery.Hearing thresholds did not change significantly in five of the six patients after placement of the "floating mass transducer." It was speculated that the high frequency component of the hearing deterioration in the remaining patient was caused by cochlear damage caused by the surgery and that the low frequency component was caused by the chronic aeration problems indirectly related to the surgery.