Hz Tone Research Articles

Evaluating Fixed Single-Point Parameters When Applied to Vestibular Evoked Myogenic Potentials: The Effect of Single Point and Signal Window.

Several studies have applied a common objective detection algorithm (fixed single point [ Fsp ]) for detection of the vestibular evoked myogenic potential (VEMP). However, fundamental parameters of Fsp , such as establishing the location and duration of a signal window, have not been examined. In addition, Fsp criterion values used for response detection have not been established for cervical VEMPs (cVEMPs) or ocular VEMPs (oVEMPs). The purpose of this article was to investigate the effect of various single points and signal windows on Fsp , as well as determining Fsp criteria to determine response presence for cVEMP and oVEMP in a group of young healthy participants. Twenty young healthy adults under the age of 30 and with no history of hearing or balance concerns were enrolled in the study protocol. Air-conducted cVEMPs and oVEMPs were evoked using 500 Hz tone bursts at 123 dB pSPL recorded at a fixed electromyography activation of 50 µV for cVEMPs and 35° gaze angle for oVEMPs. Responses were analyzed off-line using visual and objective detection. Fsp was applied to cVEMPs and oVEMPs using a range of single points and signal windows. Noise variance was lowest for cVEMPs at the latency of P1, and for oVEMPs noise variance was not significantly different across the single-point latencies. On average, extending the length of the signal window lowered the Fsp value in cVEMPs and oVEMPs. An Fsp value of 2.0 was chosen as the criterion cutoff associated with the 95th percentile during no-response conditions using group data for cVEMPs and oVEMPs, respectively. Fsp values for cVEMPs and oVEMPs were not significantly different from each other. This study established single-point latency and time-window parameters for VEMP-related applications of the Fsp detection algorithm. Fsp criteria values were established for cVEMP and oVEMP. Using these parameters, responses were detected in all participants.

Optimum stimulus for eliciting masseter vestibular-evoked myogenic potential: a comparative exploration with three different acoustic stimuli

ObjectiveTo compare the EMG rectified amplitude, absolute latencies, interpeak interval, and Interaural asymmetry parameters of masseter vestibular-evoked myogenic potential (mVEMP) elicited using clicks, 500 Hz tone bursts, and 500 Hz NB CE-chirps.MethodTwenty-five young healthy adults in the age range of 18–27 years participated for the study. mVEMP was recorded using three different acoustic stimuli i.e., clicks, 500 Hz tone bursts, and 500 Hz NB CE-chirps. mVEMP was recorded at an intensity of 125 dB peSPL with 5.1/s repetition rate. The potentials were recorded ipsilaterally using zygomatic electrode montage and were filtered between 0.1 and 3000 Hz. EMG rectification of the responses was made prior to analysis.ResultsThe latencies of P1 and N1 were significantly earlier for chirps then followed by click and tone bursts. The EMG rectified amplitude was significantly larger for the potentials obtained using chirps followed by tone bursts and then the clicks. Masseter VEMP obtained using chirps had significantly larger interpeak interval than tone bursts and clicks. The mean amplitude asymmetry ratio was greater in the potentials obtained using chirps than the other two stimuli.ConclusionThe present study reveals that 500 Hz NB CE-chirps tend to produce mVEMP with larger response amplitude and earlier latencies and thus are considered better and constructive stimuli compared to clicks and tone bursts.

Cervical vestibular evoked myogenic potential (cVEMP) findings in adults with sensorineural hearing loss (SNHL): comparisons between 500 Hz tone burst and narrowband CE-Chirp stimuli

There has been a growing interest in studying the usefulness of chirp stimuli in recording cervical vestibular evoked myogenic potential (cVEMP) waveforms. Nevertheless, the study outcomes are debatable and require verification. In view of this, the aim of the present study was to compare cVEMP results when elicited by 500 Hz tone burst and narrowband (NB) CE-Chirp stimuli in adults with sensorineural hearing loss (SNHL). Fifty adults with bilateral SNHL (aged 20–65 years) underwent the cVEMP testing based on the established protocol. The 500 Hz tone burst and NB CE-Chirp (centred at 500 Hz) stimuli were presented to each ear at an intensity level of 120.5 dB peSPL. P1 latency, N1 latency, and P1–N1 amplitude values were analysed accordingly. The NB CE-Chirp stimulus produced significantly shorter P1 and N1 latencies (p < 0.001) with large effect sizes (d > 0.80). In contrast, both stimuli elicited cVEMP responses with P1–N1 amplitude values that were not statistically different from one another (p = 0.157, d = 0.15). Additionally, age and hearing level were found to be significantly correlated (r = 0.56, p < 0.001), as were age and cVEMP amplitude for each stimulus (p < 0.001). To conclude, since both stimuli were presented at an equivalent intensity level (in dB peSPL), the shorter P1 and N1 latencies of cVEMP produced by the NB CE-Chirp stimulus (centred at 500 Hz) were unlikely due to enhanced saccular stimulation. Another more sensible reason is the temporal adjustment of the chirp stimulus.

A preliminary study on the effect of rough sound on discomfort

Acoustic roughness was proposed as a psychoacoustic metric, indicating that rough sound would attract attention or cause unpleasant feelings. Noting that some previous studies have found a negative relation between roughness and discomfort caused by noise, we intend to investigate the effect of roughness on discomfort. The 1000Hz tone was amplitude modulated with the modulation frequency range of 10-140Hz and a modulation depth of 100% as the test stimuli. Forty-eight subjects rated the discomfort caused by the test stimuli relative to the reference stimulus having a standard 1 asper roughness (i.e., 1000Hz tone with a modulation frequency of 70 Hz and a modulation depth of 100%) using the method of relative magnitude estimation. Each stimulus had a sound pressure level of 60 dB and a duration of 1 second. We identified a nonlinear pattern of discomfort with the increasing modulation frequency, with the lowest discomfort for the standard 1 asper roughness at a modulation frequency of 70 Hz. A modification weighting dependent on the modulation frequency would better quantify the roughness metric to reflect the effect of rough sound on discomfort.

Vestibular-evoked myogenic potentials and video head impulse test in cochlear otosclerosis

BackgroundOtosclerosis is one of the most common causes of hearing loss in adults with clinical onset between 20 and 40 years of age. Vestibular symptoms may be the most agonizing and primary symptom in cases with otosclerosis, so the assessment of patients is important. The vestibular-evoked myogenic potentials test (VEMP) is used to assess the saccular and the utricular functions using cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP), respectively. The video head impulse test (vHIT) which measure vestibulo-ocular reflex (VOR) to rapid impulsive head acceleration in the plane of each semicircular canal (SCC) has allowed quantitative monitoring of each canal function.MethodsTwenty subjects with bilateral otosclerosis were studied, ranging in age from 30 to 55 years, divided into two groups. One group consisted of 10 adult patients with bilateral conductive otosclerosis. The second group consisted of 10 adult patients with bilateral mixed otosclerosis. All the patients underwent cVEMP and oVEMP, using a BC 500Hz tone burst stimulus and vHIT in three planes, left anterior right posterior (LARP), right anterior left posterior (RALP), and lateral SCCs.ResultsThe findings indicate statistically significant differences in the peak-to-peak amplitudes of cVEMP and oVEMP in the two studied groups, and the mixed cases had lower amplitudes than conductive cases and a significant increase in p13 latencies. Also, there is a statistically significant difference in the lateral SCC gain between the two groups, as mixed cases had lower gain than conductive cases, but not for anterior or posterior SCCs, with no gain less than 0.8 in all three canals.ConclusionThe findings suggested that the saccule is more liable to be affected by cochlear otosclerosis followed by the utricle. The three SCCs are mostly spared.

Masseter vestibular-evoked myogenic potentials at different tone burst frequencies in healthy individuals

BackgroundMasseter vestibular-evoked myogenic potentials (mVEMP) are vestibular-dependent inhibitory reflex recorded using acoustic stimulus. mVEMP can assess important brainstem regions. mVEMP abnormalities have been reported in patients with multiple sclerosis, Parkinson’s disease, and idiopathic random eye movement disorder. The objective of the study was to record mVEMP using tone-burst stimulus at different frequencies in young healthy individuals.MethodThe study used normative study design. Thirty-two participants, aged 18–28 years with normal hearing and balance function, were recruited for the study. Simple random sampling was used for selection of participants.Data collection and analysismVEMP was recorded for all the individuals at 500 Hz,750 Hz,1000 Hz, 2000 Hz, and 4000 Hz tone burst stimuli. The p11 and n21 peaks were identified. The latency of the p11 and n21 peaks and the rectified amplitude of the p11-n21 peak complex were measured for all the participants. Wilcoxson signed-rank test was used for statistical anlysis.ResultsThe study found a 100% response rate and higher amplitude for 500 Hz and 750 Hz tone burst stimuli. However, Wilcoxson signed-rank test with Bonferroni correction showed no significant difference in amplitude (p = 0.92) between 500 and 750 Hz.ConclusionThe study recommends 500 Hz/750 Hz tone burst stimuli as an optimal frequency for recording mVEMP in young, healthy individuals. However, seeing the frequency-tuning characteristics of mVEMP in other peripheral vestibular pathologies would be interesting.

Steep temporal integration for tone detection in a multi-tone, random-frequency masker.

In the detection of a tone burst, masking by several tones with random frequencies can produce steep temporal integration. This feature was evaluated for nine normal-hearing adults for 1000-Hz tone bursts presented in a continuous train of four-tone masker bursts. Masker frequencies were randomly selected (250-4000 Hz) for each burst, with the proviso that all tones were separated by ≥0.2 oct. Bursts were 80-ms in duration; when present, signal bursts were gated synchronously with masker bursts. The observed mean temporal-integration function was exceptionally steep-thresholds improved by 26 dB as signal duration increased from 1 to 8 bursts. The results also showed that the individual differences were large, and that the mean psychometric function was exceptionally shallow, spanning a range of 35 dB between 0.6 and 0.9 proportion correct responses, consistent with previous reports. These findings were interpreted in the context of three signal-detection models, one based on the absolute-level cue, and two based on the relative-level cue via template matching; all cues were derived from the excitation patterns of the stimuli. Template-matching models were able to predict the shallow psychometric functions as observed, but all models fall short in the steepness of the observed temporal integration.

Multifrequency Analysis of Masseter Vestibular Evoked Myogenic Potentials in Young Adults.

The purpose of this study was to explore the dynamics of multifrequency tone bursts on the masseter vestibular evoked myogenic potential (mVEMP) parameters. Furthermore, it sought to determine the optimal frequency tuning of mVEMP responses. Twenty young adults with normal hearing sensitivity participated in the study. Bilateral tone burst evoked mVEMPs were obtained using the zygomatic montage at 250-, 500-, 750-, 1000-, 1500-, and 2000-Hz stimulation frequencies. Self-monitoring biofeedback was given during the procedure to confirm the tension of the masseter muscle between 49.9 and 150.6 rms. Furthermore, the electromyography (EMG) scaling was done to avoid any muscle-related irregularities. Tone burst evoked mVEMPs were found to be 100% present at the stimulation frequencies of 250, 500, 750, and 1000 Hz. There were no ear and gender effects seen for any of the frequencies. Significant shortening of the P1 and N1 latencies with increasing stimulation frequencies was observed. The peak-to-peak amplitude was the highest at 500 Hz and lowest at 2000 Hz tone bursts under both EMG scaled and unscaled conditions. The present revealed higher response rates and larger amplitudes study of mVEMP at lower frequencies, and, therefore, the frequency tuning was seen for the stimulation frequency at 500 Hz.

Establishing cervical vestibular evoked myogenic potential (cVEMP) normative data in Singapore school-aged children.

The Cervical Vestibular Evoked Myogenic Potential (cVEMP) is often employed in routine clinical practice as part of the vestibular test battery assessments. However, there is currently no well-established paediatric cVEMP normative data in Singapore. Additionally, limited literature has examined the relationship between neck length and cVEMP parameters. The main aims of this study are to 1) establish cVEMP normative data from Singaporean school-aged children aged 6-12 years old, and 2) examine if there is a significant correlation between neck length and cVEMP parameters. 31 healthy children participated in this study. Every participant was screened to ensure that they had normal auditory and vestibular profiles before completing the cVEMP procedure, which involved 500Hz tone burst through insertphones and head elevation from supine position as the method of neck contraction. The response rate in 62 ears was 98.4% at 95 dBnHL and 100% at 100 dBnHL. The mean P1 and N1 latencies were 13.96±1.17ms and 21.50±1.66ms, with a mean corrected P1-N1 amplitude of 0.88±0.34, and mean asymmetry ratio of 13±10%. Median threshold was 80 dBnHL. Significant positive correlation between neck length and both P1, N1 latencies, and significant negative correlation between neck length and corrected P1-N1 amplitude were observed. cVEMP paediatric normative data has been established for Singaporean school-aged children. The study also confirmed that neck length did have a significant influence on both latencies and corrected amplitude.

Acoustically Evoked Compound Action Potentials Recorded From Cochlear Implant Users With Preserved Acoustic Hearing.

Less traumatic intracochlear electrode design and the introduction of the soft surgery technique allow for the preservation of low-frequency acoustic hearing in many cochlear implant (CI) users. Recently, new electrophysiologic methods have also been developed that allow acoustically evoked peripheral responses to be measured in vivo from an intracochlear electrode. These recordings provide clues to the status of peripheral auditory structures. Unfortunately, responses generated from the auditory nerve (auditory nerve neurophonic [ANN]) are somewhat difficult to record because they are smaller than the hair cell responses (cochlear microphonic). Additionally, it is difficult to completely segregate the ANN from the cochlear microphonic, complicating the interpretation and limiting clinical applications. The compound action potential (CAP) is a synchronous response of multiple auditory nerve fibers and may provide an alternative to ANN where the status of the auditory nerve is of primary interest. This study is a within-subject comparison of CAPs recorded using traditional stimuli (clicks and 500 Hz tone bursts) and a new stimulus (CAP chirp). We hypothesized that the chirp stimulus might result in a more robust CAP than that recorded using traditional stimuli, allowing for a more accurate assessment of the status of the auditory nerve. Nineteen adult Nucleus L24 Hybrid CI users with residual low-frequency hearing participated in this study. CAP responses were recorded from the most apical intracochlear electrode using a 100 μs click, 500 Hz tone bursts, and chirp stimuli presented via the insert phone to the implanted ear. The chirp stimulus used in this study was CAP chirp generated using parameters from human-derived band CAPs ( Chertoff et al. 2010 ). Additionally, nine custom chirps were created by systematically varying the frequency sweep rate of the power function used to construct the standard CAP chirp stimulus. CAPs were recorded using all acoustic stimuli, allowing for within-subject comparisons of the CAP amplitude, threshold, percentage of measurable CAP responses, and waveform morphology. Considerable variation in response morphology was apparent across stimuli and stimulation levels. Clicks and CAP chirp significantly evoked identifiable CAP response more compared to 500 Hz tone bursts. At relatively high stimulation levels, the chirp-evoked CAPs were significantly larger in amplitude and less ambiguous in morphology than the click-evoked CAPs. The status of residual acoustic hearing at high frequencies influenced the likelihood that a CAP could be reliably recorded. Subjects with better preserved hearing at high frequencies had significantly larger CAP amplitudes when CAP chirp was used. Customizing the chirp stimulus by varying the frequency sweep rates significantly affected the CAP amplitudes; however, pairwise comparisons did not show significant differences between chirps. CAPs can be measured more effectively using broadband acoustic stimuli than 500 Hz tone bursts in CI users with residual low-frequency acoustic hearing. The advantage of using CAP chirp stimulus relative to standard clicks is dependent on the extent of preserved acoustic hearing at high frequencies and the stimulus level. The chirp stimulus may present an attractive alternative to standard clicks or tone bursts for this CI population when the goal is to record robust CAP responses.

Lower loss rate of serotonergically modulated neuronal accumulator for time in patients with major depressive disorder

Major depressive disorder (MDD) is characterized by dramatic and persistent worsening of mood, as well as a subjective feeling of time slowing. However, experimental data on time perception are inconsistent. As serotonergic dysfunction implicated in MDD etiology, we aim to examine time perception in MDD through the framework of lossy temporal integration model, previously also related to serotonergic transmission. Thirty-one patients with recurrent depressive disorder in partial remission and thirty control participants, without a history of psychiatric and neurological disorders, performed duration discrimination of visual stimuli (duration ranges from 3.2 to 6.4 s) and subjective minute production tasks. To infer about central serotonergic transmission, an electroencephalogram in response to the 1000 Hz tone of different intensity (50, 60, 70 and 80 dB SPL) was recorded. Patients with MDD shorten the past durations in the duration discrimination task significantly less than controls, thus being more objective. No difference in the subjective minute production was recorded. Patients with MDD have also exhibited larger auditory evoked potentials in response to the tones of high intensity (70 and 80 dB SPL) when compared with the controls. This resulted in a steeper slope of auditory evoked potentials by intensity function. These converging findings suggest a lower loss rate of neuronal temporal accumulator modulated by serotonergic transmission in patients with MDD.

Brain’s Frequency Following Responses to Low-Frequency and Infrasound

Complaints and awareness about environmental low-frequency (LF) noise and infrasound (IS) have increased in recent years, but knowledge about perceptual mechanisms is limited. To evaluate the use of the brain’s frequency-following response (FFR) as an objective correlate of individual sensitivity to IS and LF, we recorded the FFR to monaurally presented IS (11 Hz) and LF (38 Hz) tones over a 30-phon range for 11 subjects. It was found that 11-Hz FFRs were often significant already at ~0 phon, steeply grew to 20 phon, and saturated above. In contrast, the 38-Hz FFR growth was relatively shallow and continued to 60 phon. Furthermore, at the same loudness level (30 phon), the 11-Hz FFR strength was significantly larger (4.5 dB) than for 38 Hz, possibly reflecting a higher phase synchronization across the auditory pathway. Overall, unexpected inter-individual variability as well as qualitative differences between the measured FFR growth functions and typical loudness growth make interpretation of the FFR as objective correlate of IS and LF sensitivity difficult.

An Exploratory Study of Cervical Vestibular-Evoked Myogenic Potential in Users of Personal Listening Devices.

The use of personal listening devices (PLDs) is becoming increasingly popular, particularly among young people. Numerous studies have demonstrated that being exposed to PLDs can have adverse effects on the auditory system. Owing to the similarities between the auditory and vestibular systems, it is possible that the negative effects of PLD use may extend to the vestibular system, an area that has not been extensively studied. The study aimed to investigate the impact of exposure to PLDs on the vestibular system, specifically the sacculo-collic reflex assessed by the cervical vestibular-evoked myogenic potential. The current study used a cross-sectional study design. A total of 80 participants were divided into four groups based on the history of PLD exposure. Each group consisted of 20 participants who underwent cervical vestibular-evoked myogenic potential (cVEMP) testing using alternating polarity 500 Hz tone bursts. Analysis of variance (ANOVA) and Bonferroni post hoc test were used to obtain the statistically significant difference among the group. The results showed that the amplitude of p1-n1 of cVEMP was significantly reduced in individuals with longer PLD exposure duration. The study suggests that listening to music through a PLD at high levels of volume controls could be deleterious to the vestibular well-being of an individual. The study highlights the importance of being aware of the adverse effects of using PLDs to prevent potential damage to the vestibular systems.

Central Representation of Cervical Vestibular Evoked Myogenic Potentials.

Sensitivity of vestibular system to sounds (SVSS) can be measureable by cervical vestibular evoked myogenic potentials (cVEMPs). The aim of this study is to investigate central representation of vestibular system sensitivity to sound. The research was conducted in 2022-2023 by searching English language databases. The criterion for selecting documents was their overlap with the aim of this work. The animals studies were not included. The saccule is stimulated by sounds, that are transmitted through air and bone conduction. Utricle and semicircular canals are activated only by the vibrations. The afferent nerve fibers of the vestibular system project to the temporal, frontal, parietal, primary visual cortex, insula and the cingulate cortex. There is a relationship between normal results of the cVEMPs and these parameters. Improved phonemes recognition scores and word recognition scores in white noise, the efficiency of auditory training, incraed amplitude of the auditory brainstem responses to 500 HZ tone burst. Learning the first words is not only based on the hearing and other senses participate. The auditory object is a three-dimensional imaging in people's minds, when they hear a word. The words expressed by a speaker create different auditory objects in people's minds. Each of these auditory objects has its own color, shape, aroma and characteristics. For the formation of the auditory objects, all senses and whole areas of the brain contribute. Like other senses, central representation of vestibular system sensitivity to sound are also involved in the formation of auditory objects.

Asymmetric Ocular Vestibular Evoked Myogenic Potentials in Pediatric Vestibular Migraine.

Although ocular vestibular evoked myogenic potentials (oVEMP) abnormalities have been associated with vestibular migraine (VM) in adults, no studies have evaluated this in pediatric patients with VM. oVEMP asymmetry with normal cervical VEMP (cVEMP) findings may be a reliable VM biomarker in adults. We characterize VEMP results among pediatric patients with VM and benign recurrent vertigo of childhood (BRVC), a migraine precursor, and compare these results with VEMP findings from pediatric patients with nonmigrainous vestibular diagnoses. Four hundred seventy-four pediatric patients were evaluated over a 3-year period in a multidisciplinary pediatric vestibular clinic, 139 of whom met the inclusion criteria. Records were reviewed for history, audiometry, and vestibular testing results. VEMP testing was performed with a 500-Hz tone burst. Based on adult normative data, oVEMP asymmetry was defined as greater than 33% interaural difference; cVEMP asymmetry was defined as greater than 41%. Eighty subjects had VM or BRVC (mean [standard deviation] 12.8 [3.8] yr; range, 4.3-18.2 yr). Fifty-nine subjects received vestibular diagnoses other than VM or BRVC (nonmigrainous group; mean [standard deviation] age, 13.0 [3.6] yr; range, 5.14-18.9 yr). A greater proportion of the VM/BRVC group demonstrated oVEMP asymmetry with normal cVEMP as compared with the nonmigrainous group (22.5% versus 10.1%; p < 0.05). Zero subjects in the VM/BRVC group demonstrated cVEMP asymmetry versus three subjects (4.9%) of the nonmigrainous group. VM and BRVC are notable causes of migraine-related vertigo among pediatric patients. Of VM/BRVC patients, 22.5% had oVEMP asymmetry with normal cVEMP. Similar to the adult VM population, this finding may be a useful biomarker in the right clinical setting for pediatric VM. 4.

Effect of infrasound on the detectability of amplitude-modulated tonal noise

This study investigated aural detectability of wind farm infrasound and its effects on higher frequency audible tonal noise via creating a sensation of amplitude modulation. The study focused on infrasound pulses with a fundamental frequency at 0.8 Hz and 46 Hz tone which was amplitude modulated at 0.8 Hz. That tone had an amplitude modulation depth between 2 and 12 dB and tonal audibility between 5 and 17 dB. The wind farm noise (WFN) samples were selected from long-term indoor measurement data and were played at an average of 30 dBA or 62 dBG. Forty-eight participants were recruited from four different demographic groups among which some were sleep disturbed by WFN. Participants did not detect the infrasonic content of wind turbine noise above chance, either when analysed in separate groups or overall and this is consistent with previous research. Infrasound reduced the probability of amplitude modulation detection by 2.8% (95% confidence interval 0.2 to 6.1), indicating that inaudible infrasound has a small effect on the audibility of low frequency tonal noise.

Comparison of Compressed High-Intensity Radar Pulse and Tone Burst Stimulation in Vestibular Evoked Myogenic Potentials in Acute Peripheral Vestibular System Pathologies.

It is ascertained that the compressed high-intensity radar pulse (CHIRP) is an effective stimulus in auditory electrophysiology. This study aims to investigate whether Narrow Band Level Specific Claus Elberling Compressed High-Intensity Radar Pulse (NB LS CE-CHIRP) stimulus is an effective stimulus in the vestibular evoked myogenic potentials test. A case-control study was designed. Fifty-four healthy participants with no vertigo complaints and 50 patients diagnosed with acute peripheral vestibular pathology were enrolled in this study. Cervical and ocular vestibular evoked myogenic potential tests (cervical vestibular evoked myogenic potentials and ocular vestibular evoked myogenic potentials) with 500 Hz tone burst and 500 Hz Narrow Band Level Specific CE-CHIRP stimulations were performed on all participants. In addition, cervical vestibular evoked myogenic potentials and ocular vestibular evoked myogenic potentials tests with 1000 Hz tone burst and 1000 Hz Narrow Band Level Specific CE-CHIRP were performed on 24 Meniere's disease patients. P1 latency, N1 latency, amplitude, threshold, and the asymmetry ratio of responses were recorded. In healthy participants, with CHIRP stimulus, shorter P1 latency (P < .001), shorter N1 latency (P < .001), and lower threshold (P = .003) were obtained in the cervical vestibular evoked myogenic potentials test; shorter P1 latency (P < .001), shorter N1 latency (P < .001), higher amplitude (P < .001), and lower threshold (P < .001) were obtained in ocular vestibular evoked myogenic potentials test. In symptomatic ears of patients, with CHIRP stimulus, shorter P1 latency (P < .001), shorter N1 latency (P < .001), and lower threshold (P=.013 in cervical vestibular evoked myogenic potentials; P=.015 in ocular vestibular evoked myogenic potentials) were obtained in cervical vestibular evoked myogenic potentials and ocular vestibular evoked myogenic potentials tests. In asymptomatic ears of patients, with CHIRP stimulus, shorter P1 latency (P < .001) and shorter N1 latency (P < .001) were obtained in the cervical vestibular evoked myogenic potentials test; shorter P1 latency (P < .001), shorter N1 latency (P < .001), higher amplitude (P < .001), and lower threshold (P=.006) were obtained in ocular vestibular evoked myogenic potentials test. Our results suggest that due to higher response rates, shorter latencies, higher amplitude, and lower threshold values, the Narrow Band Level Specific CE-CHIRP stimulus is an effective stimulus for both cervical vestibular evoked myogenic potentials and ocular vestibular evoked myogenic potentials tests.

Characteristics of the Summating Potential Measured Across a Cochlear Implant Array as an Indicator of Cochlear Function.

The underlying state of cochlear and neural tissue function is known to affect postoperative speech perception following cochlear implantation. The ability to assess these tissues in patients can be performed using intracochlear electrocochleography (IC ECochG). One component of ECochG is the summating potential (SP) that appears to be generated by multiple cochlear tissues. Its qualities may be able to detect the presence of functional inner hair cells, but evidence for this is limited in human cochleae. This study aimed to examine the IC SP characteristics in cochlear implantation recipients, its relationship to preoperative speech perception and audiometric thresholds, and to other IC ECochG components. This is a retrospective analysis of 113 patients' IC ECochG recordings across the array in response to a 500 Hz tone burst stimulus. Responses to condensation and rarefaction stimuli were then subtracted from one another to emphasize the cochlear microphonic and added to one another to emphasize the SP, auditory nerve neurophonic, and compound action potential. Patients were grouped based on their maximum SP deflection being large and positive (+SP), large and negative (-SP), or minimal (0 SP) to further investigate these relationships. Patients in the +SP group had better preoperative speech perception (mean consonant-vowel-consonant phoneme score 46%) compared to the -SP and 0 SP groups (consonant-vowel-consonant phoneme scores 34% and 36%, respectively, difference to +SP: p < 0.05). Audiometric thresholds were lowest for +SP (mean pure-tone average 50 dB HL), then -SP (65 dB HL), and highest for 0 SP patients (70 dB HL), but there was not a statistical significance between +SP and -SP groups (p > 0.1). There were also distinct differences between SP groups in the qualities of their other ECochG components. These included the +SP patients having larger cochlear microphonic maximum amplitude, more apical SP peak electrode locations, and a more spatially specific SP magnitude growth pattern across the array. Patients with large positive SP deflection in IC ECochG have preoperatively better speech perception and lower audiometric thresholds than those without. Patterns in other ECochG components suggest its positive deflection may be an indicator of cochlear function.

Comparison of Chirp Versus Tone Burst- and Click-Evoked Masseteric Vestibular Evoked Myogenic Potentials in Normal-Hearing Adults.

This study aimed at comparing narrowband Claus Elberling level-specific chirp (NB CE-Chirp)-, click-, and tone burst-evoked masseteric vestibular evoked myogenic potentials (mVEMPs). Within-group study design and purposive sampling were performed. A total of 25 normal-hearing individuals participated in the study. The zygomatic electrode montage was used to elicit ipsilateral mVEMP responses using a 500-Hz NB CE-Chirp, a click of 100-μs duration, and a 500-Hz tone burst stimulus. Each of the responses was analyzed based on the absolute peak latency of P11 and N21, the electromyography-scaled peak-to-peak amplitude of the P11-N21 complex, and the interaural asymmetry ratio. A total of 50 ears were tested and had 100% mVEMP responses. The latencies of click-evoked and 500-Hz NB CE-Chirp-evoked mVEMPs were significantly shorter than those of 500-Hz tone burst-evoked mVEMPs (p < .05) for both ears. It revealed a significantly superior P11-N21 amplitude of the 500-Hz NB CE-Chirp and tone burst than clicks for both ears. Intraclass correlation coefficient revealed moderate to excellent test-retest reliability for mVEMP parameters across three different stimulations. The present study supports 500 Hz NB CE-Chirps as effective and reliable stimuli as tone bursts in eliciting mVEMP responses.

Utility of Inter-Frequency Amplitude Ratio of Vestibular-Evoked Myogenic Potentials in Identifying Meniere's Disease: A Systematic Review and Meta-Analysis.

A recently devised parameter of vestibular-evoked myogenic potential (VEMP) based on the principles of frequency tuning is the inter-frequency amplitude ratio (IFAR). It refers to the ratio of the amplitude of 1000 Hz tone burst evoked VEMP to 500 Hz evoked tone burst. A pathology like Meniere's disease changes the frequency response and alters the frequency tuning of the otolith organs. Because IFAR is based on the principle of frequency tuning of VEMP, it is likely to help identify Meniere's disease. Few studies in the last decade have investigated the utility of IFAR in identifying Meniere's disease. However, a systematic review and a meta-analysis on IFAR in Meniere's disease are lacking. The present study investigates whether the IFAR of VEMP helps identify Meniere's disease and differentiates it from healthy ears and other vestibular pathologies. The present study is a systematic review and a meta-analysis. The studies investigating the IFAR of cervical and ocular VEMPs in Meniere's disease, healthy controls, and other vestibular pathologies were searched across research databases such as PubMed, Science Direct, and Scopus. The search strategy was developed using the PICO (population, intervention, comparison, and outcomes) format, and Medical Subject Headings (MeSH) terms and Boolean operators were employed. The systematic review was performed using the Rayyan software, whereas the Review Manager software was used to carry out the meta-analysis. A total of 16,605 articles were retrieved from the databases. After the duplicate removal, 2472 articles remained. These were eliminated using title screening, abstract screening, and full-length inspections. A total of nine articles were found eligible for quality assessment and meta-analysis, and the New Castle-Ottawa Scale was used for quality assessment. After the data extraction, 24 six articles were found to have the desired data format for the meta-analysis. The results showed significantly higher IFAR in the affected ears of individuals in the Meniere's disease group than in the control group's unaffected ears. There was no significant difference between the unaffected ears of individuals in the Meniere's disease group and the ears of the control group. The only study on Meniere's disease and benign paroxysmal positional vertigo found significantly larger ocular VEMP IFAR in ears with Meniere's disease than in benign paroxysmal positional vertigo. This systematic review and meta-analysis found IFAR efficient in differentiating Meniere's disease from healthy controls. We also found an enhanced IFAR as a potential marker for Meniere's disease. However, more investigations are needed to confirm the utility of an enhanced IFAR value in the exclusive identification of Meniere's disease.