Displaying publications 1 - 20 of 54 in total

Abstract:
Sort:
  1. Begum, T., Reza, F., Abdullah, J.M.
    ASM Science Journal, 2011;5(2):115-121.
    MyJurnal
    Reflex epilepsy is usually induced by external stimulation, photosensitive epilepsy being the most common. Epilepsy induced by auditory stimulation is rarely studied. There are no currently published magnetoencephalographic (MEG) studies demonstrating the initiation of epileptic neuronal discharges by repeated auditory stimulations in temporal lobe epilepsy (TLE) patients. We retrospectively studied one TLE patient who underwent a MEG study to localize her epileptic focus. Auditory, somatosensory, visual and motor evoked potential studies were performed during the MEG recording. A single dipole method calculated equivalent current dipoles to localize the epileptic source. The least-squares minimization method was used to obtain the optimal solution with goodness-of-fit of greater than 80%. Periodic lateralized epileptiform discharges (PLEDs) were recorded in the temporal region when repeated auditory stimulations were done. We postulated that neuronal cortical suppression occurred during repeated stimulations which provoked epileptiform discharges (PLEDs) without any physical symptoms or aura. It was concluded that repeated stimulations could facilitate epileptiform discharges in focal area/areas in certain subjects.
    Matched MeSH terms: Acoustic Stimulation
  2. Amir Kassim A, Rehman R, Price JM
    Acta Psychol (Amst), 2018 Apr;185:72-80.
    PMID: 29407247 DOI: 10.1016/j.actpsy.2018.01.012
    Previous research has shown that auditory recognition memory is poorer compared to visual and cross-modal (visual and auditory) recognition memory. The effect of repetition on memory has been robust in showing improved performance. It is not clear, however, how auditory recognition memory compares to visual and cross-modal recognition memory following repetition. Participants performed a recognition memory task, making old/new discriminations to new stimuli, stimuli repeated for the first time after 4-7 intervening items (R1), or repeated for the second time after 36-39 intervening items (R2). Depending on the condition, participants were either exposed to visual stimuli (2D line drawings), auditory stimuli (spoken words), or cross-modal stimuli (pairs of images and associated spoken words). Results showed that unlike participants in the visual and cross-modal conditions, participants in the auditory recognition did not show improvements in performance on R2 trials compared to R1 trials. These findings have implications for pedagogical techniques in education, as well as for interventions and exercises aimed at boosting memory performance.
    Matched MeSH terms: Acoustic Stimulation/methods*
  3. Willoughby AR, de Zambotti M, Baker FC, Colrain IM
    Alcohol, 2020 May;84:1-7.
    PMID: 31539623 DOI: 10.1016/j.alcohol.2019.09.005
    There is evidence for impairment in both central nervous system (CNS) and autonomic nervous system (ANS) function with prolonged alcohol use. While these impairments persist into abstinence, partial recovery of function has been demonstrated in both systems during sleep. To investigate potential ANS dysfunction associated with cortical CNS responses (impairment in CNS-ANS coupling), we assessed phasic heart rate (HR) fluctuation associated with tones that did and those that did not elicit a K-complex (KC) during stable N2 non-rapid eye movement (NREM) sleep in a group of 16 recently abstinent alcohol use disorder (AUD) patients (41.6 ± 8.5 years) and a group of 13 sex- and age-matched control participants (46.6 ± 9.3 years). Electroencephalogram (EEG) and electrocardiogram (ECG) data were recorded throughout the night. Alcohol consumption questionnaires were also administered to the AUD patients. AUD patients had elevated HR compared to controls at baseline prior to tone presentation. The HR fluctuation associated with KCs elicited by tone presentation was significantly smaller in amplitude, and tended to be delayed in time, in the AUD group compared with the control group, and the subsequent deceleration was also smaller in AUD patients. In both groups, the increase in HR was larger and occurred earlier when KCs were produced than when they were not, and there was no difference in the magnitude of the KC effect between groups. Phasic HR changes associated with KCs elicited by tones are impaired in AUD participants, reflecting ANS dysfunction possibly caused by an alteration of cardiac vagal trafficking. However, only the timing of the HR response was found to relate to estimated lifetime alcohol consumption in AUD. The clinical meaning and implications of these novel findings need to be determined.
    Matched MeSH terms: Acoustic Stimulation*
  4. Dzulkarnain AAA, Abdullah SA, Ruzai MAM, Ibrahim SHMN, Anuar NFA, Rahim 'EA
    Am J Audiol, 2018 Sep 12;27(3):294-305.
    PMID: 30054628 DOI: 10.1044/2018_AJA-17-0087
    Purpose: The purpose of this study was to investigate the influence of 2 different electrode montages (ipsilateral and vertical) on the auditory brainstem response (ABR) findings elicited from narrow band (NB) level-specific (LS) CE-Chirp and tone-burst in subjects with normal hearing at several intensity levels and frequency combinations.

    Method: Quasi-experimental and repeated-measures study designs were used in this study. Twenty-six adults with normal hearing (17 females, 9 males) participated. ABRs were acquired from the study participants at 3 intensity levels (80, 60, and 40 dB nHL), 3 frequencies (500, 1000, and 2000 Hz), 2 electrode montages (ipsilateral and vertical), and 2 stimuli (NB LS CE-Chirp and tone-burst) using 2 stopping criteria (fixed averages at 4,000 sweeps and F test at multiple points = 3.1).

    Results: Wave V amplitudes were only 19%-26% larger for the vertical recordings than the ipsilateral recordings in both the ABRs obtained from the NB LS CE-Chirp and tone-burst stimuli. The mean differences in the F test at multiple points values and the residual noise levels between the ABRs obtained from the vertical and ipsilateral montages were statistically not significant. In addition, the ABR elicited from the NB LS CE-Chirp was significantly larger (up to 69%) than those from the tone-burst, except at the lower intensity level.

    Conclusion: Both the ipsilateral and vertical montages can be used to record ABR to the NB LS CE-Chirp because of the small enhancement in the wave V amplitude provided by the vertical montage.

    Matched MeSH terms: Acoustic Stimulation/methods*
  5. Dzulkarnain AAA, Shahrudin FA, Jamal FN, Marzuki MN, Mazlan MNS
    Am J Audiol, 2020 Dec 09;29(4):838-850.
    PMID: 32966099 DOI: 10.1044/2020_AJA-20-00049
    Purpose The purpose of this study is to investigate the influence of stimulus repetition rates on the auditory brainstem response (ABR) to Level-Specific (LS) CE-Chirp and click stimuli at multiple intensity levels in normal-hearing adults. Method A repeated-measure study design was used on 13 normal-hearing adults. ABRs were acquired from the study participants using LS CE-Chirp and click stimuli at four stimulus repetition rates (19.1, 33.3, 61.1, and 81.1 Hz) and four intensity levels (80, 60, 40, and 20 dB nHL). The ABR test was stopped at 40-nV residual noise level. Results High-stimulus repetition rates caused the ABR latencies to be longer and have reduced amplitudes in both ABR to LS CE-Chirp and click stimuli. The ABR to LS CE-Chirp Wave I, III, and V amplitudes were larger than ABR to click in almost all the stimulus repetition rates. However, there were no differences in the number of averages required to reach the stopping criterion between ABR to LS CE-Chirp and click stimulus, and between high-stimulus repetition rates and low-stimulus repetition rates. Conclusion The LS CE-Chirp at standard low-stimulus repetition rates can be used to elicit ABR for both neurodiagnostic and threshold seeking procedure.
    Matched MeSH terms: Acoustic Stimulation
  6. Nandrajog P, Idris Z, Azlen WN, Liyana A, Abdullah JM
    Asian J Neurosurg, 2017 Jul-Sep;12(3):447-453.
    PMID: 28761523 DOI: 10.4103/1793-5482.180921
    BACKGROUND: The aim of the study is to compare the amplitude and latency of the P300 event-related potential (ERP) component between a control group and patients after mild traumatic brain injury (mTBI) during 1-7 days (short duration) and 2-3 months (long duration), and to compare the outcome of neuropsychological tests between the long duration postinjury and control study groups.

    MATERIALS AND METHODS: We studied responses to auditory stimulation in two main and one subgroups, namely the control healthy group (19 patients, both ERP and neuropsychology test done), the mTBI 1 group (17 patients, only ERP done within 7 days after injury), and the mTBI 2 subgroup (the 17 mTBI 1 patients in whom a repeated ERP together with neuropsychological testing was done at 2-3 months postinjury). Auditory evoked responses were studied with two different stimuli (standard and target stimuli), where the P300 amplitude and latency were recorded from three midline sites and results were compared between the groups, as were the neuropsychological test results.

    RESULTS: There was a significant prolongation of the target P300 latency values shown by the MBI 1 group measured at the central electrode when compared to the control group, which was also seen when the mTBI 1 and mTBI 2 groups were compared. The results of the P300 amplitude values measured at the frontal electrode showed the control group to have higher readings during the presentation of standard tones when compared to the mTBI 1 group. The mTBI 2 group performed better on some neuropsychological tests.

    CONCLUSION: The latency of P300 was significantly prolonged in early mTBI patients who improved over time, and the neuropsychological testing on mTBI 2 patients showed them to be comparable to the control group. The study indicates that ERP should be used as an additional modality of investigation in mTBI patients.
    Matched MeSH terms: Acoustic Stimulation
  7. Anandan ES, Husain R, Seluakumaran K
    Atten Percept Psychophys, 2021 May;83(4):1737-1751.
    PMID: 33389676 DOI: 10.3758/s13414-020-02210-z
    Signals containing attended frequencies are facilitated while those with unexpected frequencies are suppressed by an auditory filtering process. The neurocognitive mechanism underlying the auditory attentional filter is, however, poorly understood. The olivocochlear bundle (OCB), a brainstem neural circuit that is part of the efferent system, has been suggested to be partly responsible for the filtering via its noise-dependent antimasking effect. The current study examined the role of the OCB in attentional filtering, particularly the validity of the antimasking hypothesis, by comparing attentional filters measured in quiet and in the presence of background noise in a group of normal-hearing listeners. Filters obtained in both conditions were comparable, suggesting that the presence of background noise is not crucial for attentional filter generation. In addition, comparison of frequency-specific changes of the cue-evoked enhancement component of filters in quiet and noise also did not reveal any major contribution of background noise to the cue effect. These findings argue against the involvement of an antimasking effect in the attentional process. Instead of the antimasking effect mediated via medial olivocochlear fibers, results from current and earlier studies can be explained by frequency-specific modulation of afferent spontaneous activity by lateral olivocochlear fibers. It is proposed that the activity of these lateral fibers could be driven by top-down cortical control via a noise-independent mechanism. SIGNIFICANCE: The neural basis for auditory attentional filter remains a fundamental but poorly understood area in auditory neuroscience. The efferent olivocochlear pathway that projects from the brainstem back to the cochlea has been suggested to mediate the attentional effect via its noise-dependent antimasking effect. The current study demonstrates that the filter generation is mostly independent of the background noise, and therefore is unlikely to be mediated by the olivocochlear brainstem reflex. It is proposed that the entire cortico-olivocochlear system might instead be used to alter the hearing sensitivity during focus attention via frequency-specific modulation of afferent spontaneous activity.
    Matched MeSH terms: Acoustic Stimulation
  8. Hamid K, Yusoff A, Rahman M, Mohamad M, Hamid A
    Biomed Imaging Interv J, 2012 Apr;8(2):e13.
    PMID: 22970069 MyJurnal DOI: 10.2349/biij.8.2.e13
    This fMRI study is about modelling the effective connectivity between Heschl's gyrus (HG) and the superior temporal gyrus (STG) in human primary auditory cortices. MATERIALS #ENTITYSTARTX00026;
    Matched MeSH terms: Acoustic Stimulation
  9. Jalaei B, Shaabani M, Zakaria MN
    Braz J Otorhinolaryngol, 2017 Jan-Feb;83(1):10-15.
    PMID: 27102175 DOI: 10.1016/j.bjorl.2015.12.005
    INTRODUCTION: The performance of auditory steady state response (ASSR) in threshold testing when recorded ipsilaterally and contralaterally, as well as at low and high modulation frequencies (MFs), has not been systematically studied.

    OBJECTIVE: To verify the influences of mode of recording (ipsilateral vs. contralateral) and modulation frequency (40Hz vs. 90Hz) on ASSR thresholds.

    METHODS: Fifteen female and 14 male subjects (aged 18-30 years) with normal hearing bilaterally were studied. Narrow-band CE-chirp(®) stimuli (centerd at 500, 1000, 2000, and 4000Hz) modulated at 40 and 90Hz MFs were presented to the participants' right ear. The ASSR thresholds were then recorded at each test frequency in both ipsilateral and contralateral channels.

    RESULTS: Due to pronounced interaction effects between mode of recording and MF (p<0.05 by two-way repeated measures ANOVA), mean ASSR thresholds were then compared among four conditions (ipsi-40Hz, ipsi-90Hz, contra-40Hz, and contra-90Hz) using one-way repeated measures ANOVA. At the 500 and 1000Hz test frequencies, contra-40Hz condition produced the lowest mean ASSR thresholds. In contrast, at high frequencies (2000 and 4000Hz), ipsi-90Hz condition revealed the lowest mean ASSR thresholds. At most test frequencies, contra-90Hz produced the highest mean ASSR thresholds.

    CONCLUSIONS: Based on the findings, the present study recommends two different protocols for an optimum threshold testing with ASSR, at least when testing young adults. This includes the use of contra-40Hz recording mode due to its promising performance in hearing threshold estimation.
    Matched MeSH terms: Acoustic Stimulation/methods*
  10. Mukari SZMS, Yusof Y, Ishak WS, Maamor N, Chellapan K, Dzulkifli MA
    Braz J Otorhinolaryngol, 2018 12 10;86(2):149-156.
    PMID: 30558985 DOI: 10.1016/j.bjorl.2018.10.010
    INTRODUCTION: Hearing acuity, central auditory processing and cognition contribute to the speech recognition difficulty experienced by older adults. Therefore, quantifying the contribution of these factors on speech recognition problem is important in order to formulate a holistic and effective rehabilitation.

    OBJECTIVE: To examine the relative contributions of auditory functioning and cognition status to speech recognition in quiet and in noise.

    METHODS: We measured speech recognition in quiet and in composite noise using the Malay Hearing in noise test on 72 native Malay speakers (60-82 years) older adults with normal to mild hearing loss. Auditory function included pure tone audiogram, gaps-in-noise, and dichotic digit tests. Cognitive function was assessed using the Malay Montreal cognitive assessment.

    RESULTS: Linear regression analyses using backward elimination technique revealed that had the better ear four frequency average (0.5-4kHz) (4FA), high frequency average and Malay Montreal cognitive assessment attributed to speech perception in quiet (total r2=0.499). On the other hand, high frequency average, Malay Montreal cognitive assessment and dichotic digit tests contributed significantly to speech recognition in noise (total r2=0.307). Whereas the better ear high frequency average primarily measured the speech recognition in quiet, the speech recognition in noise was mainly measured by cognitive function.

    CONCLUSIONS: These findings highlight the fact that besides hearing sensitivity, cognition plays an important role in speech recognition ability among older adults, especially in noisy environments. Therefore, in addition to hearing aids, rehabilitation, which trains cognition, may have a role in improving speech recognition in noise ability of older adults.

    Matched MeSH terms: Acoustic Stimulation/methods
  11. Jalaei B, Azmi MHAM, Zakaria MN
    Braz J Otorhinolaryngol, 2018 05 17;85(4):486-493.
    PMID: 29858160 DOI: 10.1016/j.bjorl.2018.04.005
    INTRODUCTION: Binaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported.

    OBJECTIVE: The present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations.

    METHODS: A total of 34 healthy Asian adults aged 19-30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally.

    RESULTS: While latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p<0.05). As revealed by large effect sizes (d>0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes.

    CONCLUSION: The magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults.

    Matched MeSH terms: Acoustic Stimulation/methods*
  12. Anis FN, Umat C, Ahmad K, Hamid BA
    Cochlear Implants Int, 2019 01;20(1):12-22.
    PMID: 30293522 DOI: 10.1080/14670100.2018.1530420
    OBJECTIVE: This study examined the patterns of recognition of Arabic consonants, via information transmission analysis for phonological features, in a group of Malay children with normal hearing (NH) and cochlear implants (CI).

    METHOD: A total of 336 and 616 acoustic tokens were collected from six CI and 11 NH Malay children, respectively. The groups were matched for hearing age and duration of exposure to Arabic sounds. All the 28 Arabic consonants in the form of consonant-vowel /a/ were presented randomly twice via a loudspeaker at approximately 65 dB SPL. The participants were asked to repeat verbally the stimulus heard in each presentation.

    RESULTS: Within the native Malay perceptual space, the two groups responded differently to the Arabic consonants. The dispersed uncategorized assimilation in the CI group was distinct in the confusion matrix (CM), as compared to the NH children. Consonants /ħ/, /tˁ/, /sˁ/ and /ʁ/ were difficult for the CI children, while the most accurate item was /k/ (84%). The CI group transmitted significantly reduced information, especially for place feature transmission, then the NH group (p 

    Matched MeSH terms: Acoustic Stimulation/psychology*
  13. Zakaria MN, Abdullah R, Nik Othman NA
    Ear Hear, 2018 11 22;40(4):1039-1042.
    PMID: 30461445 DOI: 10.1097/AUD.0000000000000676
    OBJECTIVES: Post-auricular muscle response (PAMR) is a large myogenic potential that can be useful in estimating behavioral hearing thresholds when the recording protocol is optimal. The main aim of the present study was to determine the influence of stimulus repetition rate on PAMR threshold.

    DESIGN: In this repeated-measures study, 20 normally hearing adults aged between 18 and 30 years were recruited. Tone bursts (500, 1000, 2000, and 4000 Hz) were used to record PAMR thresholds at 3 different stimulus repetition rates (6.1/s, 11.1/s, and 17.1/s).

    RESULTS: Statistically higher PAMR thresholds were found for the faster stimulus rate (17.1/s) compared with the slower stimulus rate (6.1/s) (p < 0.05). For all stimulus rates and frequencies, significant correlations were found between PAMR and pure-tone audiometry thresholds (r = 0.62 to 0.82).

    CONCLUSIONS: Even though the stimulus rate effect was significant at most of the tested frequencies, the differences in PAMR thresholds between the rates were small (<5 dB). Nevertheless, based on the correlation results, we suggest the use of 11.1/s stimulus rate when recording PAMR thresholds.

    Matched MeSH terms: Acoustic Stimulation/methods*
  14. Subha ST, Raman R
    Ear Nose Throat J, 2006 Oct;85(10):650, 652-3.
    PMID: 17124935
    We performed a study to determine if cerumen in the ear canal causes significant hearing loss and to ascertain if there is any correlation between the amount of cerumen and the degree of hearing loss. Our study was conducted on 109 ears in 80 patients. The results indicated that impacted cerumen does cause a significant degree of conductive hearing loss. We found no significant correlation between the length of the cerumen plug and the severity of hearing loss. Nor did we find any significant correlation between the presence of impacted cerumen and variables such as age, sex, ethnicity, or affected side.
    Matched MeSH terms: Acoustic Stimulation
  15. Zakaria MN, Jalaei B, Wahab NA
    Eur Arch Otorhinolaryngol, 2016 Feb;273(2):349-54.
    PMID: 25682179 DOI: 10.1007/s00405-015-3555-3
    For estimating behavioral hearing thresholds, auditory steady state response (ASSR) can be reliably evoked by stimuli at low and high modulation frequencies (MFs). In this regard, little is known regarding ASSR thresholds evoked by stimuli at different MFs in female and male participants. In fact, recent data suggest that 40-Hz ASSR is influenced by estrogen level in females. Hence, the aim of the present study was to determine the effect of gender and MF on ASSR thresholds in young adults. Twenty-eight normally hearing participants (14 males and 14 females) were enrolled in this study. For each subject, ASSR thresholds were recorded with narrow-band chirps at 500, 1,000, 2,000, and 4,000 Hz carrier frequencies (CFs) and at 40 and 90 Hz MFs. Two-way mixed ANOVA (with gender and MF as the factors) revealed no significant interaction effect between factors at all CFs (p > 0.05). The gender effect was only significant at 500 Hz CF (p < 0.05). At 500 and 1,000 Hz CFs, mean ASSR thresholds were significantly lower at 40 Hz MF than at 90 Hz MF (p < 0.05). Interestingly, at 2,000 and 4,000 Hz CFs, mean ASSR thresholds were significantly lower at 90 Hz MF than at 40 Hz MF (p < 0.05). The lower ASSR thresholds in females might be due to hormonal influence. When recording ASSR thresholds at low MF, we suggest the use of gender-specific normative data so that more valid comparisons can be made, particularly at 500 Hz CF.
    Matched MeSH terms: Acoustic Stimulation/methods*
  16. Salina H, Abdullah A, Mukari SZ, Azmi MT
    Eur Arch Otorhinolaryngol, 2010 Apr;267(4):495-9.
    PMID: 19727788 DOI: 10.1007/s00405-009-1080-y
    Transient-evoked otoacoustic emission (TEOAE) is a well-established screening tool for universal newborn hearing screening. The aims of this study are to measure the effects of background noise on recording of TEOAE and the duration required to complete the test at various noise levels. This study is a prospective study from June 2006 until May 2007. The study population were newborns from postnatal wards who were delivered at term pregnancy. Newborns who were more than 8-h old and passed a hearing screening testing using screening auditory brainstem response (SABRe) were further tested with TEOAE in four different test environments [isolation room in the ward during non-peak hour (E1), isolation room in the ward during peak hour (E2), maternal bedside in the ward during non-peak hour (E3) and maternal bedside in the ward during peak hour (E4)]. This study showed that test environment significantly influenced the time required to complete testing in both ears with F [534.23] = 0.945; P < 0.001 on the right ear and F [636.54] = 0.954; P < 0.001 on the left. Our study revealed that TEOAE testing was efficient in defining the presence of normal hearing in our postnatal wards at maternal bedside during non-peak hour with a specificity of 96.8%. Our study concludes that background noise levels for acceptable and accurate TEOAE recording in newborns should not exceed 65 dB A. In addition, when using TEOAE assessment in noisy environments, the time taken to obtain accurate results will greatly increase.
    Matched MeSH terms: Acoustic Stimulation*
  17. Haider HF, Bojić T, Ribeiro SF, Paço J, Hall DA, Szczepek AJ
    Front Neurosci, 2018;12:866.
    PMID: 30538616 DOI: 10.3389/fnins.2018.00866
    Tinnitus is the conscious perception of a sound without a corresponding external acoustic stimulus, usually described as a phantom perception. One of the major challenges for tinnitus research is to understand the pathophysiological mechanisms triggering and maintaining the symptoms, especially for subjective chronic tinnitus. Our objective was to synthesize the published literature in order to provide a comprehensive update on theoretical and experimental advances and to identify further research and clinical directions. We performed literature searches in three electronic databases, complemented by scanning reference lists from relevant reviews in our included records, citation searching of the included articles using Web of Science, and manual searching of the last 6 months of principal otology journals. One-hundred and thirty-two records were included in the review and the information related to peripheral and central mechanisms of tinnitus pathophysiology was collected in order to update on theories and models. A narrative synthesis examined the main themes arising from this information. Tinnitus pathophysiology is complex and multifactorial, involving the auditory and non-auditory systems. Recent theories assume the necessary involvement of extra-auditory brain regions for tinnitus to reach consciousness. Tinnitus engages multiple active dynamic and overlapping networks. We conclude that advancing knowledge concerning the origin and maintenance of specific tinnitus subtypes origin and maintenance mechanisms is of paramount importance for identifying adequate treatment.
    Matched MeSH terms: Acoustic Stimulation
  18. Rahmat S, O'Beirne GA
    Hear Res, 2015 Dec;330(Pt A):125-33.
    PMID: 26209881 DOI: 10.1016/j.heares.2015.07.013
    Schroeder-phase masking complexes have been used in many psychophysical experiments to examine the phase curvature of cochlear filtering at characteristic frequencies, and other aspects of cochlear nonlinearity. In a normal nonlinear cochlea, changing the "scalar factor" of the Schroeder-phase masker from -1 through 0 to +1 results in a marked difference in the measured masked thresholds, whereas this difference is reduced in ears with damaged outer hair cells. Despite the valuable information it may give, one disadvantage of the Schroeder-phase masking procedure is the length of the test - using the conventional three-alternative forced-choice technique to measure a masking function takes around 45 min for one combination of probe frequency and intensity. As an alternative, we have developed a fast method of recording these functions which uses a Békésy tracking procedure. Testing at 500 Hz in normal hearing participants, we demonstrate that our fast method: i) shows good agreement with the conventional method; ii) shows high test-retest reliability; and iii) shortens the testing time to 8 min.
    Matched MeSH terms: Acoustic Stimulation/methods
  19. Wilson CA, Berger JI, de Boer J, Sereda M, Palmer AR, Hall DA, et al.
    Hear Res, 2019 03 15;374:13-23.
    PMID: 30685571 DOI: 10.1016/j.heares.2019.01.009
    A common method for measuring changes in temporal processing sensitivity in both humans and animals makes use of GaP-induced Inhibition of the Acoustic Startle (GPIAS). It is also the basis of a common method for detecting tinnitus in rodents. However, the link to tinnitus has not been properly established because GPIAS has not yet been used to objectively demonstrate tinnitus in humans. In guinea pigs, the Preyer (ear flick) myogenic reflex is an established method for measuring the acoustic startle for the GPIAS test, while in humans, it is the eye-blink reflex. Yet, humans have a vestigial remnant of the Preyer reflex, which can be detected by measuring skin surface potentials associated with the Post-Auricular Muscle Response (PAMR). A similar electrical potential can be measured in guinea pigs and we aimed to show that the PAMR could be used to demonstrate GPIAS in both species. In guinea pigs, we compare the GPIAS measured using the pinna movement of the Preyer reflex and the electrical potential of the PAMR to demonstrate that the two are at least equivalent. In humans, we establish for the first time that the PAMR provides a reliable way of measuring GPIAS that is a pure acoustic alternative to the multimodal eye-blink reflex. Further exploratory tests showed that while eye gaze position influenced the size of the PAMR response, it did not change the degree of GPIAS. Our findings confirm that the PAMR is a sensitive method for measuring GPIAS and suggest that it may allow direct comparison of temporal processing between humans and animals and may provide a basis for an objective test of tinnitus.
    Matched MeSH terms: Acoustic Stimulation
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links