The relationship between distortion product otoacoustic emissions and extended high-frequency audiometry in tinnitus patients. Part 1: normally hearing patients with unilateral tinnitus.

BACKGROUND: The aim of this study was to evaluate distortion product otoacoustic emissions (DPOAEs) and extended high-frequency (EHF) thresholds in a control group and in patients with normal hearing sensitivity in the conventional frequency range and reporting unilateral tinnitus. MATERIAL/METHODS: Seventy patients were enrolled in the study: 47 patients with tinnitus in the left ear (Group 1) and 23 patients with tinnitus in the right ear (Group 2). The control group included 60 otologically normal subjects with no history of pathological tinnitus. Pure-tone thresholds were measured at all standard frequencies from 0.25 to 8 kHz, and at 10, 12.5, 14, and 16 kHz. The DPOAEs were measured in the frequency range from approximately 0.5 to 9 kHz using the primary tones presented at 65/55 dB SPL. RESULTS: The left ears of patients in Group 1 had higher median hearing thresholds than those in the control subjects at all 4 EHFs, and lower mean DPOAE levels than those in the controls for almost all primary frequencies, but significantly lower only in the 2-kHz region. Median hearing thresholds in the right ears of patients in Group 2 were higher than those in the right ears of the control subjects in the EHF range at 12.5, 14, and 16 kHz. The mean DPOAE levels in the right ears were lower in patients from Group 2 than those in the controls for the majority of primary frequencies, but only reached statistical significance in the 8-kHz region. CONCLUSIONS: Hearing thresholds in tinnitus ears with normal hearing sensitivity in the conventional range were higher in the EHF region than those in non-tinnitus control subjects, implying that cochlear damage in the basal region may result in the perception of tinnitus. In general, DPOAE levels in tinnitus ears were lower than those in ears of non-tinnitus subjects, suggesting that subclinical cochlear impairment in limited areas, which can be revealed by DPOAEs but not by conventional audiometry, may exist in tinnitus ears. For patients with tinnitus, DPOAE measures combined with behavioral EHF hearing thresholds may provide additional clinical information about the status of the peripheral hearing.

[The prevalence of tinnitus in 7-year-old children in the eastern of Poland]. / Ocena czestosci wystepowania szumów usznych wsród 7-latków w Polsce Wschodniej.

INTRODUCTION: Tinnitus in children is still rarely mentioned in medical literature. The prevalence of pediatric tinnitus has been reported to range between 3-37% and higher in children with hearing loss. OBJECTIVES: The objective of this study was to estimate the prevalence of the tinnitus in 7 years old children and to conduct statistical analysis of the relation between tinnitus and hearing loss. MATERIAL AND METHODS: In this study 60 212 children and their parents were asked about the presence of tinnitus by answering a questionnaire at home. Additionally, children were asked if they can hear noise in their ears or head, before hand hearing screening test at school was conducted. The hearing screening test was performed using screening audiometer with air conduction. RESULTS: The results showed that tinnitus was present in group of 8164 children (13.6%). Between children directly asked for tinnitus, 33% mentioned of having it. Over 75% of children did not complained of tinnitus spontaneously to parents. Children with hearing loss reported tinnitus twice more comparing to children with normal hearing. CONCLUSIONS: Tinnitus is frequent complain among 7 years old children. Children with hearing loss reported tinnitus twice more comparing to children with normal hearing. It is recommended to include to a questionnaire an inquiry about the presence of tinnitus during hearing screening tests performed recently more frequently at primary schools for early detection and diagnosis of tinnitus.

[Distortion product otoacoustic emission levels and input/output-growth functions in normal-hearing individuals with tinnitus and/or hyperacusis]. / Otoemisja produktów znieksztalcen nieliniowych slimaka oraz funkcja wejscia/wyjscia u prawidlowo slyszacych pacjentów z szumem usznym i/lub nadwrazliwoscia sluchowa.

The purpose of this study was to determine whether distortion product otoacoustic emissions (DPOAEs) can be used to distinguish among four groups with audiometrically normal-hearing sensitivity: (1) control adults without tinnitus or hyperacusis, (2) patients with tinnitus alone, (3) patients with hyperacusis alone, and (4) patients with both tinnitus and hyperacusis. Two types of DPOAE measures were evaluated: (1) the distortion product (DP-)gram measured with fixed primary levels as a function of frequency, and (2) DPOAE input/output (I/O) functions for a range of primary levels between 45 and 70 dB sound pressure level (SPL) at 1000, 2000, and 4000 Hz. DP-grams did not clearly distinguish between the control and patient groups. There was, however, a consistent trend for the three patient groups to have decreased average DP levels at 4000 and 6000 Hz; this notch in the DP-gram was not observed in the response configuration for the control group. In the three patient groups, 51 to 74% of these individuals had DP levels that were outside of the 95% confidence range for the control group. The average slopes of the I/O growth functions for each of the patient groups were consistently steeper than those for the control group; however, the slope values were indistinguishable among the patient groups. About 60% of the patients' DPOAE responses (in each group) were categorized as abnormal based on their slope values. Thus, DPOAE measures can be used with at least partial success to distinguish controls from patients with tinnitus, hyperacusis, or both tinnitus and hyperacusis, but not to discriminate among the respective patient groups. These findings suggest that the pathology represented among the patient groups is consistent at the level of the cochlea; however, diagnostic tests targeted at higher centers of processing are needed if the individuals in these groups are to be distinguished among themselves. In all participants, DPOAEs with fixed primary levels as a function of frequency were measured. There was a consistent trend for the three patient groups to have decreased average DP-gram levels at 4000 and 6000 Hz; this notch in the DP-gram was not observed in the response configuration for the control group. In the three patient groups, 51 to 74% of these individuals had DP levels that were outside of the 95% confidence range for the control group. Thus, DPOAE measures can be used with at least partial success to distinguish controls from patients with tinnitus, hyperacusis, or both tinnitus and hyperacusis, but not to discriminate among the respective patient groups. These findings suggest that the pathology represented among the patient groups is consistent at the level of the cochlea; however, diagnostic tests targeted at higher centers of processing are needed if the individuals in these groups are to be distinguished among themselves.

[Tinnitus in young patients up to 35-years old]. / Szumy uszne u osób mlodych do 35 roku zycia.

According to our observations tinnitus is becoming increasingly common amongst younger persons. About 25% of patients registered in our Tinnitus Clinic, are below the age of 35. Group of 235 tinnitus patients ranging in age from 18 to 35 years old were evaluated for this study. There were no other pre-selection criteria except the age. All of the patients answered the questions concerned with the cause of tinnitus. The results of our research indicate that infections (68.5%), noise exposure (27.7%) and stress (23.4%) are the most frequent cause of tinnitus among patients below 35 years.

[Analysis of the distortion product otoacoustic emission (DPOAE) and input/output function (I/O) in tinnitus patient with normal hearing]. / Analiza sygnalu i funkcji wzrostu otoemisji produktów znieksztalcen nieliniowych slimaka u pacjentów z szumem usznym i prawidlowa czuloscia sluchu.

Distortion Product Otoacoustic Emission (DPOAE) has been used as a tool to determine the presence of cochlear pathology. It is well known that the damage of Outer Hair Cells (OHCs) results in reduced auditory sensitivity and generation of tinnitus. At the same time tinnitus arises in normal hearing persons as well. The aim of this study was the assessment of the DPOEA amplitude and the behavior of DP I/O function in tinnitus patients with normal hearing threshold. The group of 48 tinnitus patients (92 ears) with normal hearing threshold and the control group of 30 normal hearing patients (40 ears) were investigated for this study. All subjects have undergone the measurement of DPOAE and DP I/O functions for frequencies: 1000, 2000 and 4000 Hz. In the tinnitus group there were observed the decrease in DPOAE amplitude for some frequencies and the steeper slope of I/O function. This means that the places with localized damage or dysfunction of OHCs on the basilar membrane can be responsible for the origin of tinnitus.

[The influence of high frequency hearing loss on the distortion product otoacoustic emissions in tinnitus subjects with normal hearing threshold (0,25-8 kHz)]. / Wplyw ubytków sluchu w zakresie wysokich czestotliwosci na otoemisje produktów znieksztalcen nieliniowych slimaka u osób z szumami usznymi i prawidlowym progiem slyszenia w zakresie 0,25-8kHz.

AIM OF THE STUDY: To evaluate the influence of high frequency hearing loss (> 8000 Hz) on distortion product otoacoustic emissions registered in the frequency range from 0,5 to 8 kHz. MATERIAL AND METHODS: 280 ears with tinnitus and normal hearing (0.25-8 kHz) divided into 3 groups depending on the degree of high frequency hearing loss: group A--hearing threshold up to 20 dB for 10, 12.5, 14 and 16 kHz (68 ears); group B--hearing threshold 25-40 dB HL for at least one of four EHfs (93 ears); group C--hearing threshold above 40 dB HL for at least one of four EHFs (119 ears). For each group mean audiogram and DP-gram were obtained and statistical analysis was used for comparison across these groups. RESULTS: Mean DPOAE values in group C were significantly lower in comparison with group A for the frequency range 2-8 kHz, and in comparison with group B were significantly lower for the frequency range 4-8 kHz. CONCLUSIONS: High frequency hearing loss (above 8 kHz) has a relevant influence on distortion product otoacoustic emissions registered at frequencies below 8 kHz in tinnitus patients. The greater is hearing loss above 8 kHz, the lower is DPOAE value below 8 kHz.