Audiogram Configuration Research Articles

Hearing Aid or Tinnitus Masker: Which One Is the Best Treatment for Blast-Induced Tinnitus? The Results of a Long-Term Study on 974 Patients

The aim of this longitudinal study was to explore whether a hearing aid or noise generator would be an effective audiological treatment for blast-induced chronic tinnitus. The amount of satisfaction from different hearing devices (hearing aid, noise generator, or both) during different time periods (1, 6, 12 and 24 months after fitting) was assessed. The 974 subjects enrolled in this study were Iran-Iraq war veterans, suffering from tinnitus for at least 2 years. About 84% of the subjects preferred just a hearing aid. Only 2.7% chose the noise generator, and the others preferred to use both devices. There were no significant differences between the hearing thresholds of the 3 groups. The satisfaction score for the hearing aid and combined devices increased by time but decreased for the noise generator. There was no correlation between the satisfaction score and parameters such as hearing thresholds, audiogram configuration and tinnitus pitch. We concluded that, compared with a noise generator, the most long-lasting treatment for blast-induced tinnitus is a hearing aid. The possible cause for such a performance is probably the recovery of the auditory function and neuroplasticity through the hearing aid.

Nonsyndromic hearing loss caused by USH1G mutations: widening the USH1G disease spectrum.

Currently, six genes are known to be associated with Usher syndrome type I, and mutations in most of these genes can also cause nonsyndromic hearing loss. The one exception is USH1G, which is currently only known to be involved in Usher syndrome type I and atypical Usher syndrome. A Dutch family with autosomal recessively inherited hearing loss was examined. Audiometric, ophthalmic, and vestibular evaluations were performed besides the genetic analysis. The hearing loss had an early onset with a downsloping audiogram configuration. Slight progression of the hearing loss was seen in both affected individuals. Compound heterozygous mutations in USH1G were found to segregate with the hearing loss in this family, a missense (c.310A>G, p.Met104Val) and a frameshift mutation (c.780insGCAC, p.Tyr261Alafs*96). Extensive ophthalmic and vestibular examinations demonstrated no abnormalities that are usually associated with Usher syndrome type I. This is the first family presented with nonsyndromic hearing loss caused by mutations in USH1G. Our findings expand the phenotypic spectrum of mutations in USH1G.

Childhood hearing impairment in northern Finland, etiology and additional disabilities

ObjectivesThe purpose of this study was to determine the prevalence and etiology of hearing impairment (HI) in Finnish children and to evaluate the frequency and type of additional disabilities among children with HI. MethodsSubjects consisted of 214 children with mild to profound HI ascertained until the age of 10 years. They belonged to the birth cohort spanning the years 1993–2002 in northern Finland. The clinical data were collected from the electronic patient records of the Oulu University Hospital. Age at ascertainment, degree and type of HI and audiogram configuration were determined. Risk factors and etiology of HI and co-existing disabilities were recorded. ResultsThe prevalence of childhood HI was 2.3/1000 live births (95% CI; 2.0, 2.7). The etiology of HI was genetic in 47.2%, acquired in 16.4% and unknown in 36.4% children. Among the 214 children with HI, 101 (47.2%) had other minor or major disabilities. The frequency of additional disabilities did not differ between children with mild HI and those with moderate or severe HI (p=0.78). Additional disabilities were more common (65.7%) in children with acquired HI than in children with genetic or unknown HI (43.6%) (p=0.035). ConclusionThe prevalence of childhood HI has remained unchanged in northern Finland as compared to previous studies. Genetic causes were the most common (47%) etiology of childhood HI. Among acquired causes of HI, perinatal risk factors were more common than previously. The frequency of additional disabilities was similar among children with different degrees of HI. Because almost 40% of children had one or more additional disabilities affecting development or learning, it is important to take them into consideration in rehabilitation.

Intrafamilial variable hearing loss in TRPV4 induced spinal muscular atrophy.

Mutations in the transient receptor potential vanilloid 4 gene (TRPV4) can induce a great diversity of neuropathies. Together with these neuropathies, hearing loss can occur. This study is focused on providing an audiometric phenotype description of a Dutch family with spinal muscular atrophy caused by a mutation in TRPV4. A neurological examination was repeated and pure tone and speech audiometry were performed. A large variety in neurological symptoms as well as variation in audiometric characteristics was observed. The severity of hearing loss is mild to moderate and the audiogram configuration is highly variable. The hearing loss of these patients has a progressive nature in general. The frequencies that deteriorate significantly differ between family members. When compared to presbyacusis patients, speech recognition scores of patients with a TRPV4 mutation are not clearly different. The function of TRPV4 in the inner ear is still elusive but it is suggested that TRPV4 is required for maintenance of cochlear function in stress conditions, like acoustic injury. We can neither confirm nor reject this based on the results obtained in this family. Therefore, one might consider advising patients with a TRPV4 mutation to avoid exposure to environmental influences such as noise exposure.

The clinical utility of expressing hearing thresholds in terms of the forward-going sound pressure wave

Objective: To assess the clinical utility of quantifying pure-tone hearing thresholds in terms of the forward-going sound pressure wave. Design: Sound pressure measurements in the ear canal were used to derive, with hearing threshold measurements, hearing thresholds expressed in terms of the forward-going sound pressure wave, hearing thresholds based on coupler-based calibration, and hearing thresholds expressed in terms of the sound pressure measured at the microphone. Study sample: Fifty-two adults, 18 to 34 years of age, served as the study group. Results: Audiogram configurations were similar up to 2000 Hz for the three expressions of hearing threshold, consistent with the ear canal acting as a simple volume up to this frequency. Above 2000 Hz, notable differences in hearing threshold were found, consistent with the acoustic input impedance of the ear differing from a rigid, hard-walled cavity. Repeat testing showed all three expressions of hearing threshold to be repeatable. High density measurements of hearing threshold from 3000 to 6000 Hz provided qualified support for the derivation of the forward-going sound pressure wave. Conclusions: Hearing thresholds expressed in terms of the forward-going sound pressure wave are repeatable, and with in-situ calibration, may be superior to the current coupler-based method.

Similar Phenotypes Caused by Mutations in OTOG and OTOGL

Recently, OTOG and OTOGL were identified as human deafness genes. Currently, only four families are known to have autosomal recessive hearing loss based on mutations in these genes. Because the two genes code for proteins (otogelin and otogelin-like) that are strikingly similar in structure and localization in the inner ear, this study is focused on characterizing and comparing the hearing loss caused by mutations in these genes. To evaluate this type of hearing, an extensive set of audiometric and vestibular examinations was performed in the 13 patients from four families. All families show a flat to downsloping configuration of the audiogram with mild to moderate sensorineural hearing loss. Speech recognition scores remain good (>90%). Hearing loss is not significantly different in the four families and the psychophysical test results also do not differ among the families. Vestibular examinations show evidence for vestibular hyporeflexia. Because otogelin and otogelin-like are localized in the tectorial membrane, one could expect a cochlear conductive hearing loss, as was previously shown in DFNA13 (COL11A2) and DFNA8/12 (TECTA) patients. Results of psychophysical examinations, however, do not support this. Furthermore, the authors conclude that there are no phenotypic differences between hearing loss based on mutations in OTOG or OTOGL. This phenotype description will facilitate counseling of hearing loss caused by defects in either of these two genes.

Audiometric Characteristics of a Dutch Family with a New Mutation in GATA3 Causing HDR Syndrome

We present the case of a Dutch family with a new mutation (c523_528dup) in GATA3 causing HDR syndrome. HDR syndrome is characterised by hypoparathyroidism, deafness and renal defects. In this study, we describe the audiometric characteristics of 5 patients from this family. Their hearing impairment was congenital, bilateral and symmetric. Audiograms showed mild-to-moderate hearing impairment with a flat audiogram configuration. Higher frequencies tended to be affected more strongly. Cross-sectional analyses showed no progression, and a mean audiogram was established. Psychophysical measurements in 3 HDR patients - including speech reception in noise, loudness scaling, gap detection and difference limen for frequency - were obtained to assess hearing function in greater detail. Overall, the results of the psychophysical measurements indicated characteristics of outer hair cell loss. CT scanning showed no anomalies in 3 of the HDR patients. Although 2 patients displayed vestibular symptoms, no anomalies in the vestibular system were found by vestibulo-ocular examination. Our results are in agreement with the theory that outer hair cell malfunctioning can play a major role in HDR syndrome.

Comprehensive Genetic Screening of KCNQ4 in a Large Autosomal Dominant Nonsyndromic Hearing Loss Cohort: Genotype-Phenotype Correlations and a Founder Mutation

The present study of KCNQ4 mutations was carried out to 1) determine the prevalence by unbiased population-based genetic screening, 2) clarify the mutation spectrum and genotype/phenotype correlations, and 3) summarize clinical characteristics. In addition, a review of the reported mutations was performed for better understanding of this deafness gene. The screening using 287 probands from unbiased Japanese autosomal dominant nonsyndromic hearing loss (ADNSHL) families identified 19 families with 7 different disease causing mutations, indicating that the frequency is 6.62% (19/287). While the majority were private mutations, one particular recurrent mutation, c.211delC, was observed in 13 unrelated families. Haplotype analysis in the vicinity of c.211delC suggests existence of a common ancestor. The majority of the patients showed all frequency, but high-frequency predominant, sensorineural hearing loss. The present study adds a new typical audiogram configuration characterized by mid-frequency predominant hearing loss caused by the p.V230E mutation. A variant at the N-terminal site (c. 211delC) showed typical ski-slope type audiogram configuration. Concerning clinical features, onset age was from 3 to 40 years old, and mostly in the teens, and hearing loss was gradually progressive. Progressive nature is a common feature of patients with KCNQ4 mutations regardless of the mutation type. In conclusion, KCNQ4 mutations are frequent among ADNSHL patients, and therefore screening of the gene and molecular confirmation of these mutations have become important in the diagnosis of these conditions.

No cochlear dead regions detected in non-pulsatile tinnitus patients: An assessment with the threshold equalizing noise (sound pressure level) test

One of the hypotheses on the etiology of non-pulsatile tinnitus in normal or hearing impaired patients is the existence of sharp edged cochlear dead regions (DR) flanking normal functioning hair cells. The lack of inhibition of DR on the neighboring neurons may lead to hyperactivity. Currently the Threshold Equalizing Noise test (TEN test) is the reference test to clinically assess cochlear DR. To identify cochlear DR in patients with non-pulsatile tinnitus with and without hearing loss using the TEN (sound pressure level)-test. Data were obtained from adult patients with non-pulsatile tinnitus visiting the Tinnitus Clinic of the University Hospital Antwerp. The TEN (SPL)-test was performed to assess the presence of cochlear DR for test frequencies ranging from 0.5 to 8 kHz. A total of 55 ears of 33 subjects (15 male; 18 female) with non-pulsatile tinnitus were included in the study. Subjects were divided into subgroups based on the audiometric configuration of hearing loss: Flat configuration (N = 23), high-frequency gently sloping (N = 10) and high-frequency steeply sloping (N = 22). In forty-eight ears there was no evidence of cochlear DR. In seven ears the results were inconclusive. This occurred in patients with high-frequency steeply sloping audiogram configurations. The present study does not support the TEN (SPL) test as a reliable tool for the detection of cochlear DR in a tinnitus population.

Audiogram configurations among older adults: Prevalence and relation to self-reported hearing problems

Objective: There are only a few population-based epidemiological studies on audiogram configurations among adults. The aim of this study was to investigate the prevalence of different audiogram configurations among older adults. In addition, audiogram configurations among subjects reporting hearing problems were examined. Design: Cross-sectional, population-based, unscreened epidemiological study among older adults. Study sample: The subjects (n = 850), aged 54–66 years, were randomly sampled from the population register. A questionnaire survey, an otological examination, and pure-tone audiometry were performed. Results: The most prevalent audiogram configuration among men was high-frequency steeply sloping (65.3% left ear, 51.2% right ear) and among women, high-frequency gently sloping (33.0% left ear, 31.5% right ear). There were significantly more flat configurations among women than among men. Unclassified audiograms were common especially among women (17.5%). Subjects reporting hearing difficulties, difficulties in following conversation in noise, or tinnitus, more often had a high-frequency steeply sloping configuration than those not reporting. Conclusions: High-frequency sloping audiogram configurations were common among older adults, and a high-frequency steeply sloping configuration was common among those reporting hearing problems.SumarioObjetivo: Existen pocos estudios epidemiológicos poblacionales sobre la configuración de los audiogramas en adultos. El objetivo de este estudio fue investigar la prevalencia de diferentes configuraciones audiométricas entre los adultos mayores. Además se examinaron las configuraciones audiométricas de los sujetos que reportaban problemas auditivos. Diseño: Estudio epidemiológico transversal basado en población no tamizada entre adultos mayores. Muestra: Los sujetos (n = 850), con edades entre 54 y 66 años fueron escogidos al azar de un registro poblacional. Se les aplicó un cuestionario y se realizó un examen otológico y una audiometría tonal. Resultados: la configuración audiométrica más prevalente en hombres fue la de caída abrupta en frecuencias agudas (65.3% oído izquierdo, 51.2% oído derecho) y entre las mujeres fue la caída suave en frecuencias agudas (33% oído izquierdo y 31.5% oído derecho). La configuración plana fue significativamente más frecuente en mujeres que en hombres. Los audiogramas no clasificados fueron comunes, especialmente entre las mujeres (17.5%). Los sujetos que reportaban dificultades auditivas, dificultad para seguir una conversación en ruido o acúfeno presentaban con mayor frecuencia una caída abrupta en frecuencias agudas que aquellos que no lo reportaban. Conclusiones: Las configuraciones audiométricas con caída abrupta en frecuencias agudas fueron más comunes entre quienes reportaron problemas auditivos.

Relationship Between Configuration of Audiogram and Prognosis of Hearing Loss in Sudden Deafness

Relationship Between Configuration of Audiogram and Prognosis of Hearing Loss in Sudden Deafness

Genotype–Phenotype Correlation in DFNB8/10 Families with TMPRSS3 Mutations

In the present study, genotype–phenotype correlations in eight Dutch DFNB8/10 families with compound heterozygous mutations in TMPRSS3 were addressed. We compared the phenotypes of the families by focusing on the mutation data. The compound heterozygous variants in the TMPRSS3 gene in the present families included one novel variant, p.Val199Met, and four previously described pathogenic variants, p.Ala306Thr, p.Thr70fs, p.Ala138Glu, and p.Cys107Xfs. In addition, the p.Ala426Thr variant, which had previously been reported as a possible polymorphism, was found in one family. All affected family members reported progressive bilateral hearing impairment, with variable onset ages and progression rates. In general, the hearing impairment affected the high frequencies first, and sooner or later, depending on the mutation, the low frequencies started to deteriorate, which eventually resulted in a flat audiogram configuration. The ski-slope audiogram configuration is suggestive for the involvement of TMPRSS3. Our data suggest that not only the protein truncating mutation p.T70fs has a severe effect but also the amino acid substitutions p.Ala306Thr and p.Val199Met. A combination of two of these three mutations causes prelingual profound hearing impairment. However, in combination with the p.Ala426Thr or p.Ala138Glu mutations, a milder phenotype with postlingual onset of the hearing impairment is seen. Therefore, the latter mutations are likely to be less detrimental for protein function. Further studies are needed to distinguish possible phenotypic differences between different TMPRSS3 mutations. Evaluation of performance of patients with a cochlear implant indicated that this is a good treatment option for patients with TMPRSS3 mutations as satisfactory speech reception was reached after implantation.Electronic supplementary materialThe online version of this article (doi:10.1007/s10162-011-0282-3) contains supplementary material, which is available to authorized users.

Effects of frequency compression on the intelligibility and quality of speech in noise.

Frequency-lowering technologies such as frequency compression have become common in high-end digital hearing aids. However, there are few data on the consequences of adjusting frequency compression ratio (FCR) and frequency compression cutoff (FCC). In this study, sentences at signal-to-noise ratios (SNRs) ranging from −10 to +10 dB were frequency compressed at a variety of FCRs (1.5–3) and FCCs (1–2 kHz). Frequency compression was implemented using sinusoidal modeling: the incoming signal was segmented, the spectral peaks found for each segment, and an output sinusoid at a shifted frequency was generated for each peak. Subjects were adult listeners with normal hearing or mild-moderate sensorineural loss. Intelligibility results illustrate a complex interaction between SNR and frequency compression parameters. At favorable SNRs, frequency compression had minimal effects. At less favorable SNRs, reducing FCC degraded intelligibility more than reducing FCR. At the poorest SNRs any amount of frequency compression degraded intelligibility but the specific FCC/FCR had little effect. Quality results show less interaction whereby any frequency compression was perceived as reducing speech quality. Compared to data from normal-hearing listeners, results from listeners with hearing loss were more variable and were interpretable in the context of audiogram configuration. [Work supported by NIH and GN ReSound.]

Phenotype of the first otosclerosis family linked to OTSC10

To report on the audiometric findings in the first otosclerosis family linked to OTSC10. Retrospective cohort study. A family study in a large otosclerosis family was performed, and a pedigree was constructed. Examination of all family members consisted of medical history guided by a questionnaire, pure-tone audiometry, otoscopy, and collection of blood samples for genetic linkage analysis. In addition, a selected group underwent stapedial reflex measurements and tympanometry. Cross-sectional as well as longitudinal analyses of audiometric data were performed. Eleven family members were identified as clinically affected and were all carriers of the disease haplotype. Twelve clinically unaffected family members carried the disease haplotype as well. Cross-sectional analyses of clinically affected family members showed no significant progression of air conduction (AC) thresholds, bone conduction (BC) thresholds, and air-bone gap (ABG) levels with increasing age. Longitudinal regression analyses in one family member revealed significant deterioration of AC thresholds at all frequencies. The BC thresholds showed a significant increase with advancing age at 0.5 kHz, 2 kHz, and 4 kHz. A significant progression of ABG was seen at 8 kHz. The intersubject variation, in terms of age of onset, level of progression, and audiogram configuration, was remarkable, probably due to reduced penetrance and variable expression of the disease. Long-term audiometric data in one patient, however, were useful to demonstrate progression of hearing impairment.

Prevalence of Acoustic Neuroma Associated with Each Configuration of Pure Tone Audiogram in Patients with Asymmetric Sensorineural Hearing Loss

The criteria have not yet been established for identifying the configuration of a pure tone audiogram constituting abnormal results that warrant further investigation. The purpose of this study was to determine the prevalence of acoustic neuroma associated with each configuration of the pure tone audiogram in patients with asymmetric sensorineural hearing loss (SNHL). We performed a retrospective chart review of 500 patients 15 years of age or older who had asymmetric SNHL and had undergone magnetic resonance imaging. The prevalence of acoustic neuroma in these patients was 2.6% (13 of 500). The prevalence of acoustic neuroma in each audiometric configuration was as follows: 7.1% (3 of 42) for a basin-shaped loss (odds ratio [OR] versus overall prevalence, 2.88; p = 0.23; 95% confidence interval [CI], 0.79 to 10.54), 4.7% (5 of 107) for a flat loss, 3.4% (2 of 58) for total deafness, 2.9% (1 of 34) for a high-frequency sloping audiogram, and 2.5% (2 of 81) for a high-frequency steep audiogram. The prevalence in patients with nonimproving idiopathic sudden deafness was 8.1% (OR, 3.29; p = 0.06; 95% CI, 1.13 to 9.55). In conclusion, 2.9% to 8.1% of patients with a characteristic configuration of the pure tone audiogram and symptoms of nonimproving or progressive idiopathic sudden deafness may have acoustic neuroma.

Factors influencing the outcome of idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy

Idiopathic sudden sensorineural hearing loss (ISSNHL) is an otologic emergency with an incidence of about 5-20 per 100,000 of the population per year. There is no universally accepted standard protocol for the treatment of patients with ISSNHL. Hyperbaric oxygen therapy (HBOT), was first reported to improve the outcome following acute inner ear disorders during the late 1960s by both French and German authors. The increase in perilymph oxygenation produced by HBOT provides logical basis for the use of this treatment modality in ISSNHL. We reviewed the records of 97 cases that received HBOT for SSNHL to identify the factors that may affect the treatment outcomes. The effects of age, gender, affected ear, status of the contralateral ear, symptoms associated with hearing loss, presence of a cardiovascular disease, dyslipidemia, history of diabetes mellitus, seasonal factor, smoking, degree of hearing loss, audiogram type, medical treatments provided prior to HBOT, onset time, and number of HBOT sessions were evaluated. The mean hearing gain in all cases after the HBOT was 29.5dB. The gains were statistically significant in the following cases: early onset of HBOT (p=0.016), higher number of HBOT sessions (p<0.01), steroid usage (p=0.009), low frequency-ascending and total audiogram configuration (p<0.01) and profound hearing loss (p=0.011). The success rate was significantly lower in cases with high frequency-descending audiogram configuration (p<0.001). The most important factor affected the prognosis favorably was found as steroid therapy. This retrospective study and our clinical experience suggest that HBOT has beneficial effects when administered in the early phase of the disease together with steroids. HBOT is a safe practice when used properly by an experienced hyperbaric team. In the treatment of ISSNHL, 20 sessions of HBOT at 2.5 ATA can be tolerated well besides some minor side effects. HBOT should be considered for the cases especially with total or profound hearing loss.

Mutations in the OTOF Gene in Taiwanese Patients with Auditory Neuropathy

Mutations in the OTOF gene have been found to be common causes of auditory neuropathy (AN) in Caucasians. However, the prevalence and spectrum of OTOF mutations in other populations have been inadequately documented. To explore the genetic characteristics of East Asian patients with AN, we screened for mutations in the OTOF gene by direct sequencing in 22 unrelated Taiwanese AN families (including 2 multiplex and 20 simplex families) and looked for genotype-phenotype correlations. Among the probands of the 22 AN families, a novel OTOF variant, p.E1700Q (c.5098G→C), was identified in 5 probands (23%), including 4 homozygotes and 1 heterozygote. By using restriction fragment length polymorphism to screen another 500 unrelated patients with idiopathic sensorineural hearing impairment, we further identified 1 p.E1700Q homozygote who also had clinical features compatible with AN. Furthermore, p.E1700Q was not identified in a panel of 100 normal controls, it cosegregated with the AN phenotype in the pedigrees, and the p.E1700 residue is evolutionarily conserved, consistent with its pathogenicity for AN. The associated audiologic features included progressive, prelingual, bilateral moderate-to-profound sensorineural hearing loss with a flat-type audiogram configuration. After genotyping single-nucleotide polymorphisms in the vicinity of p.E1700Q, we found that OTOF alleles with p.E1700Q shared a common haplotype, suggesting a founder effect for p.E1700Q. The predominance of the p.E1700Q mutation and the evidence of its founder effect indicate a distinct OTOF mutation spectrum in Taiwanese patients with AN.

Audiometric and Vestibular Features in a Second Dutch DFNA20/26 Family with a Novel Mutation in ACTG1

We analyzed the phenotype in a 5-generation DFNA20/26 family with a novel missense mutation in the ACTG1 gene (c.151G>A) and compared the findings to previous reports on DFNA20/26 families. Audiometric data were collected from the family members of a Dutch kindred with the novel ACTG1 mutation. Cross-sectional and/or longitudinal analyses were performed on pure tone and speech audiometry data of the mutation carriers. Age-related typical audiograms were constructed. Vestibular examination was performed in all mutation carriers. Overall, high-frequency hearing impairment, most prominent at ages over 30 years, was observed with a progression rate of 1.1 to 2.1 dB/y, increasing with frequency. It ultimately resulted in residual hearing. Speech recognition scores remained good at given pure tone average (1, 2, and 4 kHz) levels, but were slightly poorer than those at similar levels in a group of patients with presbycusis. Vestibular examination did not reveal any consistent, statistically significant abnormalities. The audiometric phenotype of the Dutch DFNA20/26 family with a novel mutation in ACTG1 was largely consistent with previous reports on DFNA20/26. Considerable variations were found in audiogram configurations within the family. This is the first known DFNA20/26 family that has experienced tinnitus.

Short-term hearing fluctuation in Meniere's disease

This study aimed to assess the extent and implications of short-term hearing fluctuation in Meniere's disease. Thirty-six subjects diagnosed with Meniere's were recruited to measure their own hearing using in-situ audiometry via a hearing aid (Widex Diva) and a portable programmer (SP3). Self-hearing tests measuring up to 14 frequency bands were conducted three times a day over eight weeks using the expanded SensogramTM. Twenty-three ears showed low frequency fluctuation while ten fluctuated in mid frequencies with some ‘double peak’ audiogram configurations. Eight ears in the later stages of Meniere's, contrary to expected, also recorded fluctuation across all frequencies. Self-hearing testing Meniere's ears over eight weeks revealed great hearing fluctuation with significant changes in audiogram configuration. It suggests that as endolymphatic hydrops progresses through the cochlea, low frequency fluctuation is followed by fluctuation in the mid frequencies, leading to fluctuation across all frequencies. Use of a self-hearing test may facilitate diagnosis and hearing aid fitting for this population, as clinical audiograms may not provide accurate information of hearing fluctuation.

Audiometric shape and presbycusis

The aim of this study was to describe the prevalence of specific audiogram configurations in a healthy, otologically screened population between 55 and 65 years old. The audiograms of 1147 subjects (549 males and 598 females between 55 and 65 years old) were collected through population registries and classified according to the configuration of hearing loss. Gender and noise/solvent-exposure effects on the prevalence of the different audiogram shapes were determined statistically. In our population ‘Flat’ audiograms were most dominantly represented (37%) followed by ‘High frequency Gently sloping’ audiograms (35%) and ‘High frequency Steeply sloping’ audiograms (27%). ‘Low frequency Ascending’ audiograms, ‘Mid frequency U-shape’ audiograms and ‘Mid frequency Reverse U-shape’ audiograms were very rare (together less than 1%). The ‘Flat’-configuration was significantly more common in females, whereas the ‘High frequency Steeply sloping’-configuration was more common in males. Exposure to noise and/or solvents did not change this finding. In addition, females with a ‘Flat’ audiogram had a significantly larger amount of overall hearing loss compared to males. Furthermore, our data reveal a significant association between the prevalence of ‘High frequency Steeply sloping’ audiograms and the degree of noise/solvent exposure, despite a relatively high proportion of non-exposed subjects showing a ‘High frequency Steeply sloping’ audiogram as well.