Otoacoustic emissions and effects of contralateral white noise stimulation on transient evoked otoacoustic emissions in diabetic children

Study of auditory pathways in type 1 diabetes mellitus through brainstem auditory evoked potentials and contralateral acoustic reflex

PURPOSE

To investigate the functionalities of the neural pathways through the auditory evoked potentials of the brainstem and the contralateral stapedial acoustic reflexes in normal-hearing individuals with type 1 diabetes mellitus, in order to detect possible alterations in the central auditory pathways.

METHODS

This is a cross-sectional study with a comparison group and a convenience sample, consisting of 32 individuals with type 1 diabetes mellitus and 20 controls without the disease. All subjects had hearing thresholds within normal limits and type A tympanometric curves. The acoustic reflex arc and brainstem auditory potentials were investigated. Statistical analyses were performed using the SPSS 17.0. The Chi-square test, Student´s t-test, and Multiple linear regression were used.

RESULTS

The auditory thresholds of the acoustic reflex were statistically lower in the group with the disease at frequencies of 0.5 kHz and 1.0 kHz in the left ear (p=0.01 and p=0.01, respectively). The absolute latencies III and V of the auditory potentials of the brainstem in the right ear and V in the left ear were increased in subjects with type 1 diabetes mellitus (p=0.03, p=0.02 and p=0.03, respectively).

CONCLUSION

The findings suggest that subjects with type 1 diabetes mellitus are more likely to present alterations in the central auditory pathways, even with auditory thresholds within normal limits.

Impact of Noise on Sound Processing at Lower Auditory System: An Electrophysiological Study

The importance of signal-to-noise ratio (SNR) is well documented in behavioral speech perception experiments and psychophysical measurements. Studies on ABR related to the encoding of signals in ipsilateral noise are very limited. The present study aimed to systematically investigate the effect of various SNRs on the latency and amplitude of ABR to a range of stimuli & to compare the latency and amplitude of ABR recorded in various ipsilateral SNRs in children and adults. We recorded auditory brain stem responses (ABR) in children and young adults for clicks, a speech token /da/ of 40 ms duration, and for a 1000 Hz tone burst in the presence of a broad band noise and quiet. There were four SNR conditions (+ 10 dB SNR, 0 dB SNR and -10 dB SNR), and the level of noise was varied, while the stimulus level was fixed at 60 dB HL. The results showed that SNR affects the latency and amplitude of the wave V peak differentially for the different stimuli. A difference in the performance of children and adults was also observed. SNR measurements using ABR provide an objective index of brainstem ability to process sound in the presence of background noise. This measure is important and can be used to assess the sound-in-noise processing ability in the difficult-to-test population such as infants and children where measures of signal-to-noise tests cannot be administered.

Evaluation of cochlear functions in infants exposed to SARS-CoV-2 intrauterine

Purpose

The novel coronavirus (SARS-CoV-2) caused an acute respiratory illness named COVID-19 and the disease spread all over the World. Fever, cough, fatigue, gastrointestinal infection symptoms form the main clinical symptoms. Pregnants and newborns form a vulnerable population and urgent measures must be addressed. Studies about the effect of COVID-19 on pregnant women, developing fetuses, and infants are limited. Various viral diseases can cause congenital or acquired, unilateral or bilateral hearing loss.

Methods

37 infants whose mother was pregnant between March 2020 and December 2020 and were born after the diagnosis of COVID- 19 during pregnancy and 36 healthy infants were included in the study. Transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE) and contralateral suppression of OAE (CLS OAE) tests were performed on all infants.

Results

According to the TEOAE results of patients and controls in the silent a statistically significant difference was observed between the two groups at 3 kHz and 4 kHz (p < 0.05). Contralateral suppression of OAE test results of patients and controls a statistically significant difference was found in all frequencies (p< 0.05). Suppression was much more effective at all frequencies in the normal group than patient group. This difference was found to be more significant at higher frequencies (2,3 and 4 kHz) (p < 0.001).

Conclusions

Our results suggest an insufficiency in medial olivocochlear efferent system in infants exposed to SARS-CoV-2 intrauterine. Cochlear functions should be examined in infants whose mothers had COVID-19.

Contralateral suppression of otoacoustic emissions in pre-school children

BACKGROUND

Contralateral suppression of otoacoustic emissions (OAEs) may serve as an index of the medial olivocochlear (MOC) reflex. To date, this index has been studied in various populations but never in pre-school children. The purpose of this study was to fill this gap and describe how the MOC reflex affects the properties of transiently evoked OAEs (TEOAEs) in this age group. In addition, the influence of the presence of spontaneous OAEs (SOAEs) in the studied ear on the suppression of TEOAEs was also investigated.

METHODS

TEOAEs with and without contralateral acoustic stimulation (CAS) by white noise were measured in 126 normally hearing pre-school children aged 3-6 years. The values of response levels, suppression by CAS, and signal-to-noise ratios (SNRs) of TEOAEs were investigated for the whole signal (global) and for half-octave frequency bands from 1 to 4 kHz. Only ears with SNR >6 dB were used in the analyses. SOAEs were acquired using the so-called synchronized SOAEs (SSOAEs) technique.

RESULTS

Ears with SSOAEs had higher response levels and SNRs than ears without SSOAEs, and suppression was lower (0.58 dB compared to 0.85 dB). Only 22% of all studied ears had an SNR >20 dB, a level recommended in some studies for measuring suppression. There were no significant effects of age or gender on TEOAE suppression.

CONCLUSIONS

Suppression levels for pre-school children did not differ appreciably from those of adults measured under similar conditions in other studies. Taken together with no effect of age in the data studied here, it seems that there is no effect of age on TEOAE suppression. However, we did find that the presence of SSOAEs had an effect on TEOAE suppression, a finding which has not been reported in earlier studies on different populations. We suggest that the presence of SSOAEs might be a crucial factor related to MOC function.

An Investigation of Hearing (250-20,000 Hz) in Children with Endocrine Diseases and Evaluation of Tinnitus and Vertigo Symptoms

Introduction  Despite much advancement in medicine, endocrine and metabolic diseases remain an important cause of morbidity and even mortality in children.

Objective  The present study was planned to investigate the evaluation of hearing that also includes high frequencies, and the presence and degree of vertigo and tinnitus symptoms in pediatric patients diagnosed with endocrine diseases such as type 1 diabetes mellitus (DM), growth hormone deficiency (GHD), obesity, idiopathic short stature, and precocious puberty

Methods  The present study included a patient group of 207 children patients diagnosed with endocrine disease (95 males, 112 females; mean age 9.71 years old [range 6–16 years old]) and a control group including 55 healthy children who do not have any kind of chronic disease (26 males, 29 females; mean age 9.33 years old [range 6–16 years old]). The subjects underwent a hearing test with frequencies between 250 and 20,000 Hz. The vestibular and tinnitus symptoms were evaluated with the Pediatric Vestibular Symptom Questionnaire.

Results  Out of 207 patients in the patient group, 5 (2.4%) had hearing loss in pure tones, 10 (4.8%) had it in high frequencies, 40 (19.3%) had tinnitus symptoms, and 18 (8.7%) had vertigo symptoms. A total of 4 out of 207 patients in the study group (1.9%), 2 out of 59 with type 1 DM patients (3.4%), 1 out of 46 with GHD (2.2%), and 1 out of 43 obesity patients (2.3%) had hearing loss, vertigo, and tinnitus symptoms.

Conclusions  Our results suggest that some childhood endocrine diseases can cause some changes in the inner ear, although the exact cause is unknown. Perhaps, a detailed hearing and balance examination should be a routine in a child diagnosed with an endocrine disease. We think it is necessary to work on more comprehensive patient groups and tests in the future.

Effects of type 1 diabetes mellitus on efferent auditory system in children and adolescents

AIM

To investigate whether type 1 diabetes mellitus (T1DM) could affect the efferent auditory system by analyzing the relationship between the activation of the medial olivocochlear reflex with disease duration, metabolic control and age at time of diagnosis.

METHOD

A total of 101 children and adolescents were evaluated. They were divided into two groups: 50 with T1DM and 51 without the disease. The participants answered a structured questionnaire containing questions about auditory complaints and were evaluated for tonal audiometry, tympanometry, acoustic reflex, otoacoustic emission by distortion product to evaluate the inhibitory effect of medial olivocochlear reflex (MOC).

RESULTS

The participants with T1DM presented changed AR (increased or absent) at all the frequencies in both ears (p < 0.05) when compared with the group without the disease. No differences were found between the DPOAE amplitudes of the individuals with and without T1DM, in both ears at all the frequencies. There were significant differences in the activation of the MOC reflex between the groups with and without T1DM, the participants with T1DM presented the absence of the inhibitory effect of the DPOAE in the right and left ears, in the frequencies of 4000 Hz (p = 0.035/0.002respectively) and 6000 Hz (p = 0.033/0.031 respectively) and 8000 Hz (p = 0.007/0.001 respectively) when compared to the healthy group. Significant differences were also observed between the groups with and without T1DM (p < 0.05) for self-reported complaints of tinitus, difficulties with the perception of speech when there was noise and distraction with noise. No association was found between the hearing complaints and the audiological measurements obtained and disease time, metabolic control and age at the time of diagnosis.

CONCLUSION

The findings suggest the presence of early auditory dysfunction of the efferent pathway in patients with T1DM.

Otoacoustic emissions from ears with spontaneous activity behave differently to those without: Stronger responses to tone bursts as well as to clicks

It has been reported that both click-evoked otoacoustic emissions (CEOAEs) and distortion product otoacoustic emissions (DPOAEs) have higher amplitudes in ears that possess spontaneous otoacoustic emissions (SOAEs). The general aim of the present study was to investigate whether the presence of spontaneous activity in the cochlea affected tone-burst evoked otoacoustic emissions (TBOAEs). As a benchmark, the study also measured growth functions of CEOAEs. Spontaneous activity in the cochlea was measured by the level of synchronized spontaneous otoacoustic emissions (SSOAEs), an emission evoked by a click but closely related to spontaneous otoacoustic emissions (SOAEs, which are detectable without any stimulus). Measurements were made on a group of 15 adults whose ears were categorized as either having recordable SSOAEs or no SSOAEs. In each ear, CEOAEs and TBOAEs were registered at frequencies of 0.5, 1, 2, and 4 kHz, and input/output functions were measured at 40, 50, 60, 70, and 80 dB SPL. Global and half-octave-band values of response level and latency were estimated. Our main finding was that in ears with spontaneous activity, TBOAEs had higher levels than in ears without. The difference was more apparent for global values, but were also seen with half-octave-band analysis. Input/output functions had similar growth rates for ears with and without SSOAEs. There were no significant differences in latencies between TBOAEs from ears with and without SSOAEs, although latencies tended to be longer for lower stimulus levels and lower stimulus frequencies. When TBOAE levels were compared to CEOAE levels, the latter showed greater differences between recordings from ears with and without SSOAEs. Although TBOAEs reflect activity from a more restricted cochlear region than CEOAEs, at all stimulus frequencies their behavior still depends on whether SSOAEs are present or not.

The 1.06 frequency ratio in the cochlea: evidence and outlook for a natural musical semitone

A frequency ratio of about 1.06 often appears in cochlear mechanics, and the question naturally arises, why? The ratio is close to that of the semitone (1.059) in music, giving reason to think that this aspect of musical perception might have a cochlear basis. Here, data on synchronised spontaneous otoacoustic emissions is presented, and a clustering of ratios between 1.05 and 1.07 is found with a peak at 1.063 ± 0.005. These findings reinforce what has been found from previous sources, which are reviewed and placed alongside the present work. The review establishes that a peak in the vicinity of 1.06 has often been found in human cochlear data. Several possible cochlear models for explaining the findings are described. Irrespective of which model is selected, the fact remains that the cochlea itself appears to be the origin of a ratio remarkably close to an equal-tempered musical semitone, and this close coincidence leads to the suggestion that the inner ear may play a role in constructing a natural theory of music. The outlook for such an enterprise is surveyed.

Spontaneous otoacoustic emissions in schoolchildren

OBJECTIVE

Spontaneous otoacoustic emissions (SOAEs) are one of the least studied types of otoacoustic emissions (OAEs). The purpose of this study was twofold: first, to determine the prevalence of SOAEs in schoolchildren, and second to test whether there was dependence between the presence or absence of SOAEs in a subject and the corresponding level of their transiently evoked OAEs (TEOAEs).

METHODS

Measurements were made on a group of normally hearing children of age 7-13 years. A technique which detects synchronized SOAEs (SSOAEs) was used in which the response to repetitive clicks (12.5/s) was analyzed in the 60-80 ms time window following each click. The matching pursuit method was used to detect SSOAEs components above the noise in this window. For comparison, TEOAEs evoked by clicks (40/s) were obtained using the standard nonlinear protocol (20 ms time window).

RESULTS

The prevalence of SOAEs was 37%, and higher in females and right ears. There was an average of 2.3 SOAEs per emitting ear. TEOAE levels were higher for ears that had SOAEs and were lower for ears that did not have any SOAEs.

CONCLUSION

Although not all normal human have SOAEs, they appear to reflect an important aspect of cochlear function. Their presence is strongly related to elevated levels of TEOAEs which are routinely used in audiological tests.

Functional hearing deficits in children with Type 1 diabetes

AIM

Hearing loss (as reflected by abnormal sound detection) is a frequently reported consequence of Type 1 diabetes mellitus. We sought to evaluate sound detection, auditory neural function and binaural processing ability in a group of school-aged participants with Type 1 diabetes and to assess their functional hearing and general communication ability.

METHODS

A range of electroacoustic, electrophysiological and behavioural test techniques were used to evaluate both cochlear and auditory neural function in 19 affected children. A cohort of matched controls was also assessed.

RESULTS

Although all of the participants with Type 1 diabetes enjoyed normal sound detection, 9 of the 19 (47%) showed evidence of auditory pathway abnormality with evoked potential latencies and/or amplitudes beyond age-related norms. Auditory brainstem response interpeak latencies (wave I-V) were longer than in matched controls [ 95% confidence interval (95% CI); 0.10, 0.28 ms: P < 0.001] and wave V amplitudes were reduced (95% CI; -0.21, 0.00 μV: P = 0.02). Binaural speech perception in noise was also impaired (95% CI; 0.82, 3.17 dB: P = 0.002) and perceptual ability was correlated with degree of neural disruption in the auditory brainstem (r = 0.662, P = 0.003).

CONCLUSIONS

Hearing deficits severe enough to restrict communication and threaten academic progress were common on our group of school-aged children with Type 1 diabetes. Evaluation of both cochlear and auditory neural function may form an important part of the standard management regime for children with diabetes.

The Hyperactivity of Efferent Auditory System in Patients with Schizophrenia: A Transient Evoked Otoacoustic Emissions Study

OBJECTIVE

Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia.

METHODS

Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements.

RESULTS

We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05).

CONCLUSION

The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients.

Effects of Type 2 Diabetes on Otoacoustic Emissions and the Medial Olivocochlear Reflex

Objective

To demonstrate if cochleopathy in patients with type 2 diabetes with normal audiometric hearing threshold can be detected with otoacoustic emissions or medial olivocochlear (MOC) reflex measurements.

Study Design

Cross-sectional study.

Setting

Tertiary university teaching hospital.

Methods

The study involved 40 type 2 diabetic patients and 24 healthy volunteers. All participants who showed normal otoscopic findings, hearing thresholds, and acoustic admittance were included. Cochlear activity of participants was evaluated by means of distortion product otoacoustic emissions (DPOAEs) and transient otoacoustic emissions (TOAEs). The MOC reflex was evoked with contralateral acoustic stimulation and recorded with DPOAEs and TOAEs.

Result

A comparison of DPOAE and TOAE levels with a t test between patient and control groups revealed no significant difference ( P > .05). A comparison of the MOC reflex response between the 2 groups also revealed no statistically significant difference ( P > .05).

Conclusion

Although decreased OAE amplitude levels were found in diabetic patients, there was no statistically significant difference in OAEs and MOC reflex. Additional studies are needed to evaluate the role of OAEs and MOC reflex in normal-hearing patients with diabetes.

Cochleopathy in Egyptian adolescents with Type 1 diabetes mellitus

BACKGROUND

Diabetic neuropathy is recognized as the most common clinical picture of nervous system disorders caused by diabetes mellitus (DM). Although peripheral and autonomic nervous system involvements are frequently encountered, data about the incidence of central diabetic neuropathies is limited.

OBJECTIVE

Our study aimed to detect early asymptomatic auditory impairment whether at the level of outer hair cells (OHCs), inner hair cells (IHCs) and or olivo-cochlear bundle and the relationship between these abnormalities and other variables such as diabetes duration, degree of the metabolic control, or presence of microvascular complications.

SUBJECTS AND METHODS

Seventy five adolescents with Type 1 DM and thirty three healthy controls participated in the study. Duration of DM, glycated hemoglobin (HbA1c) levels, microvascular complications were analyzed. All underwent basic audiological assessment to ensure normal hearing and normal middle ear function. Other tests comprised: transiently evoked otoacoustic emissions (TEOAEs) testing OHCs, TEOAEs with contralateral suppression (testing the integrity of olivo-cochlear bundle) and threshold equalizing noise (TEN) testing IHCs as evidenced by dead regions within the cochlea.

RESULTS

Early asymptomatic OHCs involvement as reflected by partial pass in 33.3% of cases with diminished suppression as compared to 9.1% control group. Eleven patients (7.33%) showed positive TEN Test reflecting resistance of IHCs to hyperglycemic injury. Diabetic patients had significantly higher amplitude on TEOAEs with noise suppression when compared to controls (P=0.002). The mean difference in amplitude of TEOAEs before and after suppression was significantly higher in diabetics with microvascular complications when compared to diabetic children without complications at all frequencies (P<0.001 for all). Duration of diabetes and microvascular complications (nephropathy, peripheral and autonomic neuropathy) were not correlated with the lack of suppression except for retinopathy (P=0.02). In contrast, poor metabolic control was associated with poor suppression (r=-0.443, P=0.001).

CONCLUSIONS

Cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold. It should be considered as early manifestation of diabetic neuropathy which is related to the degree of metabolic control and retinopathy independent of other microvascular complications.

Otoacoustic emissions in neonates measured with different acquisition protocols

OBJECTIVE

The purpose of the study was to investigate the properties of neonatal transiently evoked otoacoustic emissions (TEOAEs) recorded with three most popular stimulation protocols. Differences between the recorded TEOAEs with and without spontaneous otoacoustic emissions (SOAEs), were also assessed. In addition two more issues were addressed: (i) the effect of windowing on the TEOAE responses; and (ii) the contribution of the TEOAE segment from 12.5 to 20 ms to the overall TEOAE response.

METHODS

TEOAEs and SOAEs were recorded from 50 normal hearing neonates using linear, non-linear, QuickScreen and standard synchronized SOAE stimulation protocols. Global and half-octave-band values of TEOAE reproducibility and response level were used to assess statistical differences in the recorded responses. Furthermore protocol differences were evaluated in different recording windows from 2.5 to 12.5 and 12 to 20 ms.

RESULTS

Data from the linear protocol presented TEOAE parameters with the highest values. The differences between recordings with longer and shorter acquisition windows were especially apparent in 1-1.4 kHz frequency range. Furthermore the data have shown that the low frequency TEOAE components are a significant part of the TEOAE response, especially in ears without SOAEs.

CONCLUSIONS

The results suggest that TEOAE protocols using short recording windows (i.e. QuickScreen) can be used only for a fast detection of a valid TEOAE. For more sophisticated clinical analyses the standard 20 ms TEOAE recording window is more appropriate. The presence of SOAEs significantly influences TEOAEs. Ears with SOAEs presented higher values of TEOAE parameters especially in the 2-4 kHz range. On the other hand, in the ears without SOAEs low frequency components contribute more to the signal.

Contralateral suppression of otoacoustic emissions: input-output functions in neonates

Background

The literature suggests that contralateral acoustic stimulation (CAS) alters the amplitude of the distortion product otoacoustic emissions (DPOAEs), but it is still unknown whether the DPOAE Input/Output (I/O) functions are also affected. To elucidate this aspect of the DPOAEs, the present study assessed the effects of CAS on DPOAE I/O functions at the frequencies of 2 kHz and 4 kHz, in a sample of term neonatal subjects.

Material/Methods

Sixty randomly selected neonates were included in the study. The DPOAE I/O functions were obtained at 2 kHz and 4 kHz, in the presence of a 60 dB SPL broad band-contralateral white noise, using the TDH39 headphones contralaterally. DPOAEs were recorded up to a stimulus level of L₂=35 dB peSPL.

Results

Significant DPOAE amplitude suppression effects were observed at various L₂ stimulus levels for both tested frequencies at 2 and 4 kHz. In contrast, the corresponding DPOAE slopes showed various alterations that were not statistically significant.

Conclusions

The data from the present study show that contralateral acoustic stimulation significantly affects only the amplitude of the DPOAE I/O functions; the slope is affected, but not significantly. This observation can shed light on the nature of CAS, suggesting that the latter is primarily a linear phenomenon without the cochlear compression and non-linear components seen in the healthy cochlea. From the available data it is not possible to infer whether the sample size has influenced the obtained results and the study should be repeated with a larger sample size and assessing more frequencies.

Cochlear efferent innervation and function

PURPOSE OF REVIEW

This review covers topics relevant to olivocochlear-efferent anatomy and function for which there are new findings in papers from 2009 to early 2010.

RECENT FINDINGS

Work within the review period has increased our understanding of medial olivocochlear (MOC) mechanisms in outer hair cells, MOC-reflex tuning, MOC effects on distortion product otoacoustic emissions, the time course of MOC effects, MOC effects in psychophysical tests and on understanding speech, MOC effects in attention and learning, and lateral efferent function in binaural hearing. In addition, there are new insights into efferent molecular mechanisms and their effect on cochlear development.

SUMMARY

Techniques for measuring efferent effects using otoacoustic emissions are now well developed and have promise in clinical applications ranging from predicting which patients are susceptible to acoustic trauma to characterizing relationships between efferent activation and learning disabilities. To realize this promise, studies are needed in which these techniques are applied with high standards.