Sinusoidal Tones Research Articles

The relationship between tinnitus pitch and the edge frequency of the audiogram in individuals with hearing impairment and tonal tinnitus

Some theories of mechanisms of tinnitus generation lead to the prediction that the pitch associated with tonal tinnitus should be related to the “edge frequency” of the audiogram, f e, the frequency at which hearing loss worsens relatively abruptly. However, previous studies testing this prediction have provided little or no support for it. Here, we reexamined the relationship between tinnitus pitch and f e, using 11 subjects selected to have mild-to-moderate hearing loss and tonal tinnitus. Subjects were asked to compare the pitch of their tinnitus to that of a sinusoidal tone whose frequency and level were adjusted by the experimenter. Prior to testing in the main experiment, subjects were given specific training to help them to avoid octave errors in their pitch matches. Pitch matches made after this training were generally lower in frequency than matches made before such training, often by one or two octaves. The matches following training were highly reproducible. A clear relationship was found between the values of f e and the mean pitch matches following training; the correlation was 0.94. Generally, the pitch matches were close in value to the values of f e.

Early gamma-band responses reflect anticipatory top-down modulation in the auditory cortex

For efficient and fast encoding of our complex acoustic environment, not only aspects of bottom-up processing are significant, but rather top-down influences such as attention, memory, and anticipation promote specific behavior and perception. Neural oscillatory activity in the gamma-range (30–80 Hz) is discussed as a conceivable candidate to represent very rapid modulations of top-down factors.We investigated effects of anticipation on early gamma-band responses (GBRs) of the EEG and event-related potentials (ERPs) in response to tone sequences. These sequences were composed of six sinusoidal tones, which could be either regularly ascending or descending in frequency. Thus, the sequences reflected a good continuation of pitch, which also resulted in the buildup of strong expectancies for the upcoming stimulus within the sequence. However, some of the tone sequences contained a violation of the good continuation of pitch at the third or fifth tone position.The early phase-locked portion of the gamma-band activity was significantly increased when tones were in line with the good continuation of sequences compared to deviant tones. Further, a pronounced early negative ERP response, starting at 150 ms, was elicited by deviant tones at the third and fifth position.Our results support the notion that gamma-band oscillations reflect perceptual grouping processes of concurrent sounds and anticipatory top-down modulation, which involves some of the first stages of auditory information processing.

Issues on the pulse-width dependence and the shape of acoustic radiation induced static displacement pulses in solids

Recent experimental results showing the pulse width independence and the flat topped shape of static displacement generated during finite amplitude sinusoidal ultrasonic tone burst propagation in solids and the contradicting previous results reported in the literature are considered. The pulse width independence is analytically confirmed and the flat topped shape is explained by considering the progressive spatial and time domain shapes of the static strain and displacement pulses. A numerical simulation of the finite amplitude longitudinal ultrasonic wave propagation in solids has been performed to further verify the pulse width independence of the static displacement pulse.

Bone Conduction Auditory Steady State Response: Investigations into Reducing Artifact

Auditory steady state responses (ASSRs) can be reliably recorded in sleeping neonates and can be used to estimate hearing thresholds in individuals with normal or impaired hearing. However, artifactual responses can contaminate recordings, particularly when recording bone conduction ASSRs. The aim of this investigation was to study the presence of electromagnetic artifact in bone conduction ASSRs and to investigate methods of reducing the amplitude of the artifact. Using a simulation of a patient, ASSR recordings were obtained to multiple frequency bone-conducted stimuli using the research MASTER system. ASSR stimuli were sinusoidal tones with the carrier frequencies 500, 1000, 2000, and 4000 Hz that were 100% amplitude modulated at 83, 87, 91, and 95 Hz, respectively. After the assessment of different equipment layouts, the effects of (1) altering the analog-to-digital conversion rates and (2) screening the transducer cable and B-71 transducer and connecting the screens to ground were investigated. For ASSR recordings, artifacts were observed at the modulation rates of the 1000-, 2000-, and 4000-Hz carrier frequencies. As expected, the artifact was proportional to stimulus intensity and was observed when using sampling rates of 1000 and 2000 Hz but not 1250 and 1600 Hz. Altering the electrode lead/transducer cable layout and orientation of the B-71 transducer significantly affected the amplitude of the artifact. Screening of the B-71 transducer and cable and connecting the screens to ground reduced the amplitude of the artifact to a level that was not significantly above background noise. A mu-metal screen had a significantly greater effect than aluminum or copper. If stimulus artifact is present in the recorded EEG, for certain choices of carrier frequency and sampling rate it is possible to record artifactual signals at the same modulation rates as those used to elicit ASSRs. This is problematic as the artifact may then be misinterpreted as an ASSR response. The results from this study have demonstrated that careful attention to equipment layout, choice of sampling rate, using grounded screens to screen the B-71 transducer and transducer cable can all be effective in reducing the level of stimulus artifact.

Single-Trial Evoked Brain Responses Modeled by Multivariate Matching Pursuit

We present a new approach to the analysis of brain evoked electromagnetic potentials and fields. Multivariate version of the matching pursuit algorithm (MMP) performs an iterative, exhaustive search for waveforms, which optimally fit to signal structures, persistent in all the responses (trials) with the same time of occurrence, frequency, phase, and time width, but varying amplitude. The search is performed in a highly redundant time--frequency dictionary of Gabor functions, i.e., sines modulated by Gaussians. We present the feasibility of such a single-trial MMP analysis of the auditory M100 response, using an illustrative dataset acquired in a magnetoencephalographic (MEG) measurement with auditory stimulation with sinusoidal 1-kHz tones. We find that the morphology of the M100 estimate obtained from simple averaging of single trials can be very well explained by the average reconstruction with a few Gabor functions that parametrize those single trials. The M100 peak amplitude of single-trial reconstructions is observed to decrease with repetitions, which indicates habituation to the stimulus. This finding suggests that certain waveforms fitted by MMP could possibly be related to physiologically distinct components of evoked magnetic fields, which would allow tracing their dynamics on a single-trial level.

The automatic sound representation relies on salient segmentation of the acoustic input

Event Abstract Back to Event The automatic sound representation relies on salient segmentation of the acoustic input Annekathrin Weise1*, S. Grimm2, D. Müller1 and E. Schröger1 1 Institute of Psychology I, University of Leipzig, Germany 2 University of Barcelona, Spain The automatic sound representation can be investigated by utilizing the mismatch negativity (MMN) component of the event-related potential. Several findings revealed that the automatic representation of pure sinusoidal tones is limited to the initial 300-ms. This temporal constraint was reflected in the absence of MMN to deviations occurring beyond the initial 300-ms. However, a salient transient (gap, noise burst) segmenting such tones re-gained MMN and thus, resulted in a full-fledged automatic sound representation. The present study examined whether the salient segmentation of the acoustic input is pivotal for the entire automatic sound representation. We tested for MMN to duration deviants (40 % decrement) embedded in a sequence of 1000 ms long standard tones with linear increasing frequency (sweeps). In different conditions standards and deviants contained (I) no segmenting event, (II) a non-salient plateau (short sequence with the tone frequency remaining constant), or (III) a salient noise burst. No MMN was elicited to unstructured sweeps and to sweeps containing the plateau. Hence, neither permanent gradual changes characterizing sweeps nor a non-salient event within the sweeps can improve the automatic sound representation. Importantly, the sweeps segmented by a noise burst evoked MMN. Moreover, the salient noise burst itself elicited the P1-N1-P2 complex (which is associated with structuring elements) whereas the non-salient element (i.e., the plateau) did not. Consequently, salient segmentation of the acoustic input is essential for an entire automatic sound representation. Conference: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications, Budapest, Hungary, 4 Apr - 7 Apr, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: Weise A, Grimm S, Müller D and Schröger E (2009). The automatic sound representation relies on salient segmentation of the acoustic input. Conference Abstract: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications. doi: 10.3389/conf.neuro.09.2009.05.044 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Mar 2009; Published Online: 24 Mar 2009. * Correspondence: Annekathrin Weise, Institute of Psychology I, University of Leipzig, Leipzig, Germany, akweise@uni-leipzig.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Annekathrin Weise S. Grimm D. Müller E. Schröger Google Annekathrin Weise S. Grimm D. Müller E. Schröger Google Scholar Annekathrin Weise S. Grimm D. Müller E. Schröger PubMed Annekathrin Weise S. Grimm D. Müller E. Schröger Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Stochastic resonance in auditory steady-state responses in a magnetoencephalogram

Objective To see whether stochastic resonance can be triggered in the auditory steady-state responses (ASSRs) in a magnetoencephalogram (MEG). Methods We measured ASSRs to 1 kHz sinusoidal tone modulated at 40 Hz with various intensities of white noise and obtained its power and degree of phase synchrony. Results Group statistics showed a significant enhancement in phase synchrony of ASSR by the presence of white noise of appropriate intensity. Tests on individual subjects showed that the data of four out of nine subjects exhibited enhancements in power or phase synchrony. Conclusions The ASSRs exhibit stochastic resonance of the so-called I-type (I for information) shown in phase synchrony when responding to modulated sinusoidal sound superimposed with weak white noise. Significance The gamma-band component and other oscillatory components in the brain activity have been recently ascribed by some researchers to the result of stochastic resonance caused by internal noise in the brain. Therefore the presence of stochastic resonance in ASSRs may be evidence to the hypothesis that ASSRs are related to the ongoing gamma-band component.

Enhanced discrimination of low-frequency sounds for subjects with high-frequency dead regions

Research using animals suggests that a lesion in the basal portion of the cochlea, causing a high-frequency 'dead region', leads to cortical reorganization, such that frequencies just below the edge frequency of the dead region, fe, become over-represented. We set out to determine if this reorganization has functional benefits. Two groups of subjects were tested, with and without acquired high-frequency dead regions, as assessed using the TEN(HL) test. For the ears with dead regions, the value of fe was close to 1000 or 1500 Hz. The two groups were matched in terms of audiometric thresholds for frequencies below fe and in terms of age. Three subjects with unilateral dead regions (with matched low-frequency audiometric thresholds across ears) were also tested. Three tasks were used: (i) frequency discrimination of sinusoidal tones. The level of every stimulus was roved over a 12-dB range to reduce the salience of loudness cues. The center frequencies used ranged from 250 Hz to just below fe; (ii) detection of sinusoidal amplitude modulation of a sinusoidal carrier. Carrier frequencies of 500 and 800 Hz were used with all subjects, and an additional carrier frequency of 1200 Hz was used for ears with fe close to 1500 Hz and their matched counterparts. Modulation frequencies were 4, 50 and 100 Hz; (iii) identification of consonants in nonsense syllables. The syllables were lowpass filtered at 1000 or 1500 Hz (depending on the value of fe) and complementary highpass-filtered noise was presented to prevent use of information from neurons tuned above fe. For the frequency-discrimination task, the ears with dead regions showed a significant local improvement ('enhanced' thresholds) for frequencies just below fe, as has been reported previously. For the subjects with unilateral dead regions, the enhancement occurred only for the ears with dead regions. For the amplitude-modulation detection task, thresholds were generally lower for the ears with dead regions than for the ears without, and this effect was statistically significant. For the subjects with unilateral dead regions, thresholds were lower for the ears with dead regions than for the ears without. Consonant identification was significantly better for the ears with than without dead regions, and this was true for the subjects with unilateral dead regions. We conclude that a dead region at high frequencies is associated with a better ability to process information at low frequencies. These effects may reflect cortical plasticity induced by the dead regions.

Carbon monoxide

Carbon monoxide (CO), a by-product released during the degradation of heme by heme oxygenases (HOS EC 1.14.99.3) in animals, plays a major role as neurotransmitter, regulator of sinusoidal tone, inhibitor of platelet aggregation, and suppressor of acute hypertensive response, and most of above effects are similar to or mediated by nitric oxide (NO), another signal molecule in both the animal and plant kingdoms. Previous result demonstrated that NO could act as a promoter of plant cell elongation, acting similarly to IAA, inducing morphogenetic responses leading to expansion in plant tissues. Recent observations revealed that CO is an inducer of cell expansion in wheat root segments, acting similarly to IAA and NO. Evidence also indicated that IAA could result in either the potent induction of HO-1 transcript or endogenous CO releasing in wheat root segments. Additionally, our results suggested that above CO signaling might be related to NO/cGMP, Ca2+ and even ROS-dependent pathways. In this addendum, combined with other previous results, we further proposed a possible hypothesis for CO signaling role in regulation of plant root development induced by auxin.

All-Optical Analog-to-Digital Conversion Using Inherent Multiwavelength Phase Shift in LiNbO$_{3}$ Phase Modulator

All-optical analog-to-digital conversion utilizing inherent multiwavelength phase shift in lithium niobate phase modulator is proposed. In the experimental demonstration, a wavelength-tunable continuous-wave laser diode and a lithium niobate phase modulator are used to quantize the sinusoidal tone electrical analog signal. Using 16 different wavelengths, an effective number of bits of 4.3-bit has been obtained after software sampling measurement. Benefits of the presented approach in this letter are its simple realization of the phase shift and high stability.

Regulation of Sinusoidal Perfusion in Portal Hypertension

Portal hypertension, a major complication of cirrhosis, is caused by both increased portal blood flow and augmented intrahepatic vascular resistance. Even though the latter is primarily caused by anatomical changes, it has become clear that dynamic factors contribute to the increased hepatic vascular resistance. The hepatic sinusoid is the narrowest vascular structure within the liver and is the principal site of blood flow regulation. The anatomical location of hepatic stellate cells, which embrace the sinusoids, provides a favorable arrangement for sinusoidal constriction, and for control of sinusoidal vascular tone and blood flow. Hepatic stellate cells possess the essential contractile apparatus for cell contraction and relaxation. Moreover, the mechanisms of stellate cell contraction are better understood, and many substances which influence contractility have been identified, providing a rationale and opportunity for targeting these cells in the treatment of portal hypertension in cirrhosis.

Auditory Adaptation in Voice Perception

Perceptual aftereffects following adaptation to simple stimulus attributes (e.g., motion, color) have been studied for hundreds of years. A striking recent discovery was that adaptation also elicits contrastive aftereffects in visual perception of complex stimuli and faces [1-6]. Here, we show for the first time that adaptation to nonlinguistic information in voices elicits systematic auditory aftereffects. Prior adaptation to male voices causes a voice to be perceived as more female (and vice versa), and these auditory aftereffects were measurable even minutes after adaptation. By contrast, crossmodal adaptation effects were absent, both when male or female first names and when silently articulating male or female faces were used as adaptors. When sinusoidal tones (with frequencies matched to male and female voice fundamental frequencies) were used as adaptors, no aftereffects on voice perception were observed. This excludes explanations for the voice aftereffect in terms of both pitch adaptation and postperceptual adaptation to gender concepts and suggests that contrastive voice-coding mechanisms may routinely influence voice perception. The role of adaptation in calibrating properties of high-level voice representations indicates that adaptation is not confined to vision but is a ubiquitous mechanism in the perception of nonlinguistic social information from both faces and voices.

Picosecond flat-top pulse generation by low-bandwidth electro-optic sinusoidal phase modulation

We report the first experimental demonstration to our knowledge of a microwave frequency upshifting system based on phase modulation. A sequence of flat-top optical and RF pulses at a repetition rate of 18.22 GHz, each with a FWHM time width of approximately 25 ps, is generated from a sinusoidal RF tone of only 3.680 GHz, in good agreement with our analytical and numerical calculations. A simple explanation of this technique based on Talbot effect theory is provided. The practical limitations and capabilities of the phase-modulation-based frequency upshifting approach for ultrabroadband RF waveform generation are also discussed.

Ocena zgodności progów słyszenia w badaniach potencjałów słuchowych stanu ustalonego (ASSR), audiometrii tonalnej i słuchowych potencjałów wywołanych pnia mózgu (ABR) u młodych osób z prawidłowym słuchem

One of the basic audiological parameter in estimation of hearing sensitivity is hearing threshold. The need for an objective tool to efficiently predict the audiogram caused that the use and importance of ASSR method is growing in recent times. However, the technique is quite new and needs to be still improved. Aim of the study was the estimation of behavioral audiogram in comparison with ABR and ASSR threshold of young adults with normal hearing. The study sample included 9 subjects with normal hearing (18 ears) with no abnormalities in otoscopy. Behavioral hearing thresholds and ASSRs to carrier frequencies of 0.5, 1, 2, and 4 kHz were obtained. The ASSRs were assessed with Bio-logic MASTER system by the use of four sinusoidal tones both frequency--and amplitude--modulated given simultaneously to every ear for each carrier frequency. The potentials are collected, averaged and analyzed in this method by the fast Fourier transform to yield statistically significant responses. Electrophysiologic threshold responses for click ABR stimuli for the same carrier frequencies for right and left ear were obtained by the use of Bio-logic Navigator Pro unit. Differences and correlations between the ASSRs, ABRs and the behavioral thresholds were determined. We discovered that the values of pure tone audiograms and ABRs thresholds values differ from ASSRs considerably. We could also observed that the difference between behavioral and ABRs threshold is less than for behavioral and ASSRs threshold. To conclude, this study shows that auditory steady-state responses technique is not useful method in estimating of hearing threshold of young adults with normal hearing.

Simultaneously measured behavioral and electrophysiological hearing thresholds in a bottlenose dolphin (Tursiops truncatus)

Dolphin auditory thresholds obtained via evoked potential audiometry may deviate from behavioral estimates by 20 dB or more. Differences in the sound source, stimulus presentation method, wave form, and duration may partially explain these discrepancies. To determine the agreement between behavioral and auditory evoked potential (AEP) threshold estimates when these parameters are held constant, behavioral and AEP hearing tests were simultaneously conducted in a bottlenose dolphin. Measurements were made in-air, using sinusoidal amplitude-modulated tones continuously projected via a transducer coupled to the pan region of the dolphin's lower jaw. Tone trials were presented using the method of constant stimuli. Behavioral thresholds were estimated using a 50% correct detection. AEP thresholds were based on the envelope following response and 50% correct detection. Differences between AEP and behavioral thresholds were within +/-5 dB, except at 10 kHz (12 dB), 20 kHz (8 dB), 30 kHz (7 dB), and 150 kHz (24 dB). In general, behavioral thresholds were slightly lower, though this trend was not significant. The results demonstrate that when the test environment, sound source, stimulus wave form, duration, presentation method, and analysis are consistent, the magnitude of the differences between AEP and behavioral thresholds is substantially reduced.

Differential processing of terminal tone parts within structured and non-structured tones

Recent studies utilizing the mismatch negativity (MMN) event-related potential (ERP) revealed that when a repetitive sequence of sinusoidal tones is presented, the occasional insertion of a short deviation into some of the tones leads to the elicitation of an MMN only if it occurs during the initial 300 ms, but not beyond. In contrast, deviations occurring in speech sounds elicit MMN even beyond 300 ms. We conducted two experiments to resolve this conflict. We hypothesised that an additional transient within an otherwise unstructured tone may overcome this limitation. First, we tested for MMN to a deviance at the terminal part of a 650 ms tone which did or did not contain a gap. Only when the tone included the gap, MMN was obtained. Second, we compared the gap condition with two noise conditions, in which the gap was replaced by modulated white noise. The noise conditions differed with respect to the saliency of the perceived interruption of the tone. In all three conditions, MMN was elicited. These results demonstrate that structuring a sinusoidal tone by a gap or a noise interval is sufficient to regain MMN. It is suggested that the introduction of an additional transient triggers a new integration window overcoming the temporal constraints of automatic tone representation. This resolves the seeming contradiction between MMN studies using tonal and speech sounds.

Comparison of Responses of Neurons in the Mouse Inferior Colliculus to Current Injections, Tones of Different Durations, and Sinusoidal Amplitude-Modulated Tones

We made in vivo whole cell patch-clamp recordings from the inferior colliculus of young-adult, anesthetized C57/Bl6 mice to compare the responses to constant-current injections with the responses to tones of different duration or to sinusoidal amplitude-modulated (SAM) tones. We observed that voltage-dependent ion channels contributed in several ways to the response to tones. A sustained response to long tones was observed only in cells showing little accommodation during current injection. Cells showing burst-onset firing during current injection showed a small response to SAM tones, whereas burst-sustained cells showed a good response to SAM tones. The hyperpolarization-activated nonselective cation channel I(h) had a special role in shaping the responses: I(h) was associated with an increased excitability, with chopper and pauser responses, and with an afterhyperpolarization following tones. Synaptic properties were more important in determining the responses to tones of different durations. A short-latency inhibitory response appeared to contribute to the long-pass response in some cells and short-pass and band-pass neurons were characterized by their slow recovery from synaptic adaptation. Cells that recovered slowly from synaptic adaptation showed a relatively small response to SAM tones. Our results show an important role for both intrinsic membrane properties -- most notably the presence of I(h) and the extent of accommodation -- and synaptic adaptation in shaping the response to tones in the inferior colliculus.

Stimulus intensity affects early sensory processing: Sound intensity modulates auditory evoked gamma-band activity in human EEG

We studied the effect of different sound intensities on the auditory evoked gamma-band response (GBR). Previous studies observed oscillatory gamma activity in the auditory cortex of animals and humans. For the visual modality, it has been demonstrated that the GBR can be modulated by top–down (attention, memory) as well as bottom-up factors (stimulus properties). Therefore, we expected to find a sound intensity modulation for the auditory GBR. 21 healthy participants without hearing deficits were investigated in a forced-choice discrimination task. Sinusoidal tones were presented at three systematically varied sound intensities (30, 45, 60 dB hearing level). The results of the auditory evoked potentials were predominantly consistent with previous studies. Furthermore, we observed an augmentation of the evoked GBR with increasing sound intensity. The analysis indicated that this intensity difference in the GBR amplitude most likely arises from increased phase-locking. The results demonstrate a distinct dependency between sound intensity and gamma-band oscillations. Future experiments that investigate the relationship between auditory evoked GBRs and higher cognitive processes should therefore select stimuli with an adequate sound intensity and control this variable to avoid confounding effects. In addition, it seems that gamma-band activity is more sensitive to exogenous stimulus parameters than evoked potentials.

Delayed auditory processing underlying stimulus detection in Down syndrome

Down syndrome (DS) is characterized by intellectual disability and development of dementia that are attributed to similar neuropathological features as observed in Alzheimer's disease (AD). The aim of this study was to investigate whether DS patients have similar impairment of preattentive auditory processing as observed in AD. Sinusoidal tones were presented to DS patients and healthy controls, and evoked auditory evoked fields (AEF) were measured with a whole-head magnetoencephalography (MEG) system. Patients with DS had significantly delayed and attenuated N100m, and delayed but not attenuated P50m responses over both hemispheres. Present results indicate that preattentive auditory processing underlying stimulus detection is impaired in DS. Given that anticholinergic drugs modulate AEFs, degeneration of cholinergic system in DS could contribute to the damaged auditory processing.

All-Optical Analog-to-Digital Conversion Based on Polarization-Differential Interference and Phase Modulation

A novel approach of an all-optical analog-to-digital converter is proposed and demonstrated. One single-phase modulator and a continuous-wave laser diode are used to quantize the sinusoidal tone analog signal. Software sampling measurements yielded an effective number of bits of 4.1. Benefits of the proposed setup are its simple design, high bandwidth, and stability. The scheme is primarily limited in the optical domain by the speed of the phase modulator and in electronic domain by electrical comparators and logic devices