Hearing Research (HEARING RES)

Publications in this journal

• Article: Gray Matter in the Human Brain: Differences Associated with Tinnitus and Hearing Loss

  Boyen K, Langers DRM, de Kleine E, van Dijk P
  Hearing Research 03/2012;
• Article: Finite-element modelling of the configuration changes of the ossicular chain with static pressure

  W. F. Decraemer, W. R. J. Funnell, S. L. R. Gea, J. A. N. Buytaert, J. J. J. Dirckx
  Hearing Research 01/2010; 263(1-2):242.
• Article: Realistic morphological 3-D model of the gerbil middle ear, including bone and soft tissue structures

  J. A. N. Buytaert, M. Dierick, Patric Jacobs, J. J. J. Dirckx
  Hearing Research 01/2010; 263(1-2):246.
• Article: Towards high-realism physics based models of middle ear mechanics: High definition morphology, precise materials parameters and introduction of non-linearity

  J. J. J. Dirckx, J. Aernouts, J. R. M. Aerts, J. A. N. Buytaert, J. A. M. Soons
  Hearing Research 01/2010; 263(1-2):241-242.
• Article: Dynamics of Spectro-Temporal Tuning in Primary Auditory Cortex

  B.Shechter, HD.Dobbins, P Marvit, DA Depireux
  Hearing Research 01/2009; 256(1-2):118-130.
• Article: Acute changes in frequency responses of inferior colliculus central nucleus (ICC) neurons following progressively enlarged restricted spiral ganglion lesions.

  Russell L Snyder, Ben H Bonham, Donal G Sinex
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  ABSTRACT: Immediate effects of sequential and progressively enlarged spiral ganglion (SG) lesions were recorded from cochleas and inferior colliculi. Small SG-lesions produced modest elevations in cochlear tone-evoked compound action potential (CAP) thresholds across narrow frequency ranges; progressively enlarged lesions produced progressively higher CAP-threshold elevations across progressively wider frequency ranges. No comparable changes in distortion product otoacoustic emissions (DPOAEs) amplitudes were observed consistent with silencing of auditory nerve sectors without affecting organ of Corti function. Frequency response areas (FRAs) of inferior colliculus (IC) neurons were recorded before and immediately after SG-lesions using multi-site silicon arrays fixed in place with recording sites arrayed along IC frequency gradient. Individual post-lesion FRAs exhibited progressively elevated response thresholds and diminished response amplitudes at lesion frequencies, whereas responses at non-lesion frequencies were either unchanged or enhanced. Characteristic frequencies were shifted and silent areas were introduced within these FRAs. Sequentially larger lesions produced sequentially larger shifts in CF and/or enlarged silent areas within affected FRAs, producing immediate changes in IC frequency organization. These results contrast with those from the auditory nerve, extend previous reports of experience-induced plasticity in the auditory CNS, and support results indicating afferent convergence onto ICC neurons across broad frequency bands.
  Hearing Research 11/2008; 246(1-2):59-78.
• Article: Time-frequency analysis of click-evoked otoacoustic emissions by means of a minimum variance spectral estimation-based method.

  Z G Zhang, V W Zhang, S C Chan, B McPherson, Y Hu
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  ABSTRACT: This paper proposes a new minimum variance spectral estimation (MVSE)-based time-frequency analysis (TFA) technique for click-evoked otoacoustic emissions (CEOAEs). The MVSE is a popular spectrum analysis method which can yield a high frequency resolution compared to other nonparametric spectral analysis procedures. The conventional MVSE is extended to a TFA method by windowing the observation data to obtain a time-frequency representation for the signal under study. Inspired by the adaptive window selection process in wavelet transform and based on the time-frequency characteristics of CEOAEs, the window size of the windowed MVSE (WMVSE) is given a small value at high frequencies and a large value at low frequencies. The adaptive window size selection yields the proposed frequency-dependent WMVSE (FDWMVSE). The FDWMVSE method integrates the advantages of the adaptive window selection in wavelet transform with the fine frequency resolution of MVSE. Experimental results show that the FDWMVSE can achieve satisfactory time-frequency resolution and reveal meaningful time-frequency features when applied to synthesized and real CEOAEs.
  Hearing Research 10/2008; 243(1-2):18-27.
• Article: Distribution of two-pore-domain potassium channels in the adult rat vestibular periphery.

  Paul Popper, John Winkler, Christy B Erbe, Alexandara Lerch-Gaggl, Wolfgang Siebeneich, P Ashley Wackym
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  ABSTRACT: Constitutively active background or "leak" two-pore-domain potassium (K(+)) channels (Kcnk family), as defined by lack of voltage and time dependency are central to electrical excitability of cells by controlling resting membrane potential and membrane resistance. Inhibition of these channels by several neurotransmitters, e.g. glutamate, or acetylcholine, induces membrane depolarization and subsequent action potential firing as well as increases membrane resistance amplifying responses to synaptic inputs. In contrast, their opening contributes to hyperpolarization. Because of their central role in determining cellular excitability and response to synaptic stimulation, these channels likely play a role in the differential effects of vestibular efferent neurons on afferent discharge. Microarray data from previous experiments showed Kcnk 1, 2, 3, 6, 12 and 1 5 mRNA in Scarpa's ganglia. Real-time RT-PCR showed Kcnk 1, 2, 3, 6, 12 and 15 mRNA expression in Scarpa's ganglia and Kcnk 1, 2, 3, 6, 12 but not 15 mRNA expression in the crista ampullaris. We studied the distribution of two-pore-domain potassium channels K(2P)1.1, 2.1, 3.1 and 6.1 like immunoreactivity (corresponding to Kcnk genes 1, 2, 3 and 6) in the vestibular periphery. K(2P)1.1 (TWIK 1) immunoreactivity was detected along nerve terminals, supporting cells and blood vessels of the crista ampullaris and in the cytoplasm of neurons of the Scarpa's ganglia. K(2P)2.1 (TREK 1) immunoreactivity was detected in nerve terminals and transitional cells of the crista ampullaris, in the vestibular dark cells and in neuronal fibers and somata of neurons of Scarpa's ganglia. K(2P)3.1 (TASK 1) immunoreactivity was detected in supporting cells and transitional cells of the crista ampullaris, in vestibular dark cells and in neuron cytoplasm within Scarpa's ganglia. K(2P)6.1 (TWIK 2) immunoreactivity was detected in nerve terminals, blood vessels hair cells and transitional cells of the crista ampullaris and in the somata and neuron fibers of Scarpa's ganglia.
  Hearing Research 10/2008; 246(1-2):1-8.
• Article: Involvement of platelet-derived growth factor receptor-beta in maintenance of mesenchyme and sensory epithelium of the neonatal mouse inner ear.

  Hisamitsu Hayashi, Takahiro Kunisada, Nobuyuki Takakura, Mitsuhiro Aoki, Keisuke Mizuta, Yatsuji Ito
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  ABSTRACT: Platelet-derived growth factor receptor (PDGFR) signaling has been demonstrated to play a pivotal role in early embryonic development. Although the expression of PDGF in the inner ear has been studied by RT-PCR, how PDGFR is involved there remains largely unclear. In the current study, we used the antagonistic anti-PDGFR-beta antibody, APB5, to investigate the role of PDGFR-beta in the neonatal mouse inner ear. PDGFR-beta was detected immunohistochemically in the mesenchymal tissue adjacent to the sensory epithelium of the inner ear, and a ligand for PDGFR-beta was detected around the sensory epithelium. To determine whether this expression plays a functional role, we injected APB5 into neonates to block the function of PDGFR-beta. Mesenchymal tissue defects and abnormal capillaries with irregular shapes, especially in the cochlear lateral wall, were detected in APB5-treated mice. The results of a TUNEL assay revealed that not only the adjacent mesenchymal cells but also the sensory epithelial cells underwent cell death. These results indicate that PDGFR-beta signals are required for the survival of the capillary and mesenchymal cells in the neonatal mouse inner ear and also indirectly implicate these signals in the survival of the sensory epithelium.
  Hearing Research 10/2008; 245(1-2):73-81.
• Article: Effects of velocity and motion-onset delay on detection and discrimination of sound motion.

  Stephan Getzmann
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  ABSTRACT: The effect of velocity on auditory motion processing in combination with a motion-onset delay was investigated in two experiments. The detection of motion onset and discrimination of motion direction were studied, employing a psychophysical reaction time task. Listeners were presented with sounds moving along the frontal horizontal plane in a dark anechoic environment. Response times (RTs) were measured, while the velocity (20 degrees /s, 40 degrees /s, 80 degrees /s) and the motion-onset delay (the time between sound onset and start of motion: 0, 200, 500, 1000 ms) were varied. Listeners responded faster with higher velocity and longer motion-onset delay. In particular, with higher velocity, the function relating RT to motion-onset delay had a steeper initial decrease than with lower velocities. The results are in line with psychophysical studies of the minimum audible movement angle and recent electrophysiological data about the role of motion velocity in auditory motion processing. The effect of motion-onset delay is discussed with regard to a dynamic temporal window, in which auditory spatial information is integrated until enough information is accumulated to trigger motion detection.
  Hearing Research 10/2008; 246(1-2):44-51.
• Article: Lexical tone recognition with spectrally mismatched envelopes.

  Ning Zhou, Li Xu
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  ABSTRACT: It has been shown that frequency-place mismatch has detrimental effects on English speech recognition. The present study investigated the effects of mismatched spectral distribution of envelopes on Mandarin Chinese tone recognition using a noise-excited vocoder. In Experiment 1, speech samples were processed to simulate a cochlear implant with various insertion depths. The carrier bands were shifted basally relative to the analysis bands by 1-7 mm in the cochlea. Nine normal-hearing Mandarin Chinese listeners participated in this experiment. Basal shift of the carriers only slightly affected tone recognition. The resistance of tone recognition to spectral shift can be attributed to the overall amplitude contour cues that are independent from spectral manipulations. Experiment 2 examined the effects of frequency compression, where widened analysis bands by 2, 6, and 10 mm were compressively allocated to narrower carrier bands. Five of the 9 subjects participated in Experiment 2. It appears that the expanded frequency information especially on the low frequency end can compensate for the distortion from frequency compression. Thus, spectral shift might not pose a severe problem for tone recognition, and allocation of wider frequency range to include more low frequency information might be beneficial for tone recognition.
  Hearing Research 10/2008; 246(1-2):36-43.
• Article: Impact of occupational noise on pure-tone threshold and distortion product otoacoustic emissions after one workday.

  Jörg Müller, Thomas Janssen
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  ABSTRACT: The aim of this study was to investigate whether distortion product otoacoustic emissions (DPOAEs) are a suitable means for detecting small changes in cochlear amplifier functionality due to occupational noise exposure of one workday and whether efferent reflex strength of the medial olivocochlear bundle is able to predict the ear's susceptibility to noise. High-resolution (Deltaf(2)= 47 Hz) DPOAEs were recorded between 3.5 and 4.5 kHz at close-to-threshold primary tone levels. For comparison, pure-tone audiometry was conducted. Efferent reflex strength was measured by means of DPOAEs at a specific frequency with and without contralateral acoustic stimulation. A statistically significant change was found for pure-tone thresholds (DeltaL(ht)=+1.6+/-3.0 dB, n=155) and DPOAE levels (DeltaL(dp)=-1.0+/-2.4 dB, n=646; L(2)=20 dB SPL) in factory workers but not in office workers (DeltaL(ht)=-1.3+/-3.3 dB, n=80; DeltaL(dp)=0.0+/-1.6 dB, n=336) (control group). However, the influence of systematic biases due to, e.g. ear probe calibration or measurement sequence effects, has to be considered. Moreover, there was no significant correlation between efferent reflex strength and shifts in pure-tone thresholds or shifts in DPOAE levels. Thus, the applied measures of efferent reflex strength do not seem to be suitable for predicting temporary changes in hearing capability.
  Hearing Research 10/2008; 246(1-2):9-22.
• Article: Application of frequency modulated chirp stimuli for rapid and sensitive ABR measurements in the rat.

  Christopher Spankovich, Linda J Hood, D Wesley Grantham, Daniel B Polley
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  ABSTRACT: Rodents have proven to be a useful model system to screen genes, ototoxic compounds and sound exposure protocols that may play a role in hearing loss. High-throughput screening depends upon a rapid and reliable functional assay for hearing loss. This study describes the use of a frequency modulated (FM) chirp stimulus as an alternative to the click to derive a rapid assessment of auditory brainstem response (ABR) threshold in the rodent. We designed a rising frequency A-chirp based upon the spatial mapping of preferred frequency along the rat basilar membrane to provide a more synchronous and equipotent input across the length of the cochlea. We observed that the ABR wave I and wave IV amplitudes evoked by the A-chirp were significantly greater than the click and that A-chirp minimum response thresholds were lower than the click. Subsequent analyses compared the efficacy of the A-chirp to linear, time-reversed and amplitude-reversed chirps and confirmed that the A-chirp was most effective chirp configuration. These data suggest that the A-chirp may be optimally suited as a single screening broad-frequency stimulus for rapid ABR threshold estimations in the rodent and could serve to complement more detailed frequency-specific physiologic and behavioral estimates of hearing threshold.
  Hearing Research 10/2008; 245(1-2):92-7.
• Article: Neonatal nicotine exposure impairs development of auditory temporal processing.

  Wei Sun, Anna Hansen, Liyan Zhang, Jianzhong Lu, Daniel Stolzberg, Kari Suzanne Kraus
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  ABSTRACT: Accurate temporal processing of sound is essential for detecting word structures in speech. Maternal smoking affects speech processing in newborns and may influence child language development; however, it is unclear how neonatal exposure to nicotine, present in cigarettes, affects the normal development of temporal processing. The present study used the gap-induced prepulse inhibition (gap-PPI) of the acoustic startle response to investigate the effects of neonatal nicotine exposure on the normal development of gap detection, a behavioral testing procedure of auditory temporal resolution. Neonatal rats were injected twice per day with saline (control), 1mg/kg nicotine (N-1 mg) or 5 mg/kg nicotine (N-5 mg) from postnatal day 8-12 (P8-P12). During the first month after birth, rats showed poor gap-PPI in all three groups. At P45 and P60, gap-PPI in control rats improved significantly, whereas rats exposed to nicotine exhibited less improvement. At P60, the gap-detection threshold in the N-5 mg group was significantly higher than in the control group, suggesting that neonatal nicotine exposure affects the normal development of gap-detection acuity. Additionally, 1h after receiving an acute nicotine injection (1 mg/kg), gap-PPI recorded in adult rats from the N-5 mg group showed a temporary significant improvement. These results suggest that neonatal nicotine exposure reduces gap-PPI implying an impairment of the normal development of auditory temporal processing by inducing changes in cholinergic systems.
  Hearing Research 10/2008; 245(1-2):58-64.
• Article: Kv1.1 channel subunits are not necessary for high temporal acuity in behavioral and electrophysiological gap detection.

  Paul D Allen, Nicholas Schmuck, James R Ison, Joseph P Walton
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  ABSTRACT: The Kv1.1 potassium channel subunit, encoded by the Kcna1 gene, is heavily expressed in the auditory brainstem and is thought to have a critical role in producing the high temporal precision of action potentials characteristic of the auditory system. Our intent was to determine whether temporal acuity was reduced in Kcna1 null-mutant (-/-) mice, compared to wild-type (+/+) and heterozygotic mice (+/-), as measured by the encoding of gaps in the inferior colliculus by near-field auditory evoked potentials (NFAEP) or behavioral gap detection (BGD) using a prepulse inhibition paradigm. NFAEPs were collected at 40, 60 and 80 dB SPL with gap durations from 0.5 to 64 ms. BGD data were collected using silent gaps in 70 dB noise from 1 to 15 ms in duration. There were no systematic effects of Kcna1 genotype on NFAEP recovery functions, NFAEP latencies, or the time constant for BGD, but there was a small reduction in asymptotic prepulse inhibition for the longest gap stimuli in -/- mice. Gap thresholds were approximately 1-2 ms across genotypes, stimulus conditions, and paradigms. These data suggest that the neural pathways encoding behaviorally relevant, rapid auditory temporal fluctuations are not limited by the absence of Kv1.1 expression.
  Hearing Research 10/2008; 246(1-2):52-8.
• Article: Neurite outgrowth on cultured spiral ganglion neurons induced by erythropoietin.

  Nurdanat Berkingali, Athanasia Warnecke, Priya Gomes, Gerrit Paasche, Jan Tack, Thomas Lenarz, Timo Stöver
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  ABSTRACT: The morphological correlate of deafness is the loss of hair cells with subsequent degeneration of spiral ganglion neurons (SGN). Neurotrophic factors have a neuroprotective effect, and especially brain-derived neurotrophic factor (BDNF) has been demonstrated to protect SGN in vitro and after ototoxic trauma in vivo. Erythropoietin (EPO) attenuates hair cell loss in rat cochlea explants that were treated with gentamycin. Recently, it has also been shown that EPO reduces the apoptose rate in hippocampal neurons. Therefore, the aim of the study was to examine the effects of EPO on SGN in vitro. Spiral ganglion cells were isolated from neonatal rats and cultured for 48 h in serum-free medium supplemented with EPO and/or BDNF. Results showed that survival rates of SGN were not significantly improved when cultivated with EPO alone. Also, EPO did not further increase BDNF-induced survival of SGN. However, significant elongation of neurites was determined when SGN were cultivated with EPO alone. Even though a less than additive effect was observed, combined treatment with BDNF and EPO led to a significant elongation of neurites when compared to individual treatment with BDNF or EPO. It can be concluded that EPO induces neurite outgrowth rather than promoting survival. Thus, EPO presents as an interesting candidate to enhance and modulate the regenerative effect of BDNF on SGN.
  Hearing Research 10/2008; 243(1-2):121-6.
• Article: Comparison of noise-induced changes of auditory brainstem and middle latency response amplitudes in rats.

  Jiri Popelar, Jolana Grecova, Natalia Rybalko, Josef Syka
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  ABSTRACT: Auditory brainstem responses (ABRs) and middle latency responses (MLRs) were compared after noise exposure to elucidate the specific effects of a loud sound on the central auditory system in rats. Rats were exposed twice for 1 h to broad-band noise (BBN) of 118 dB SPL (first exposure) and 122 dB SPL (second exposure) with an interval between the exposures of three weeks. The first noise exposure produced threshold shifts (TSs) amounting to 5-45 dB, and the second exposure resulted in 40-70 dB TSs. The slope of MLR amplitude-intensity functions (AIFs) increased significantly in correlation with the TS, resembling loudness recruitment. However, maximal MLR amplitudes measured at 8 kHz increased after the first and second noise exposures to almost equal values in individual animals regardless of the TS. In addition, maximum MLR amplitude enhancement was dependent on pre-exposure MLR voltage, probably reflecting the level of metabolic activity or neurotransmitter processes in individual animals. In contrast to MLR amplitudes, ABR amplitudes were suppressed after noise exposure without changing the slope of ABR AIFs. The MLR changes reflect the specific effects of noise exposure on the central auditory system.
  Hearing Research 10/2008; 245(1-2):82-91.
• Article: Neural tonotopy in cochlear implants: an evaluation in unilateral cochlear implant patients with unilateral deafness and tinnitus.

  Katrien Vermeire, Andrea Nobbe, Peter Schleich, Peter Nopp, Maurits H Voormolen, Paul H Van de Heyning
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  ABSTRACT: In cochlear implants, the signal is filtered into different frequency bands and transmitted to electrodes along the cochlea. In this study the frequency-place function for electric hearing was investigated as a means to possibly improve speech coding by delivering information to the appropriate cochlear place. Fourteen subjects with functional hearing in the contralateral ear have been provided with a MED-EL cochlear implant in the deaf ear in order to reduce intractable tinnitus. Pitch scaling experiments were performed using single-electrode, constant-amplitude, constant-rate stimuli in the implanted ear, and acoustic sinusoids in the contralateral ear. The frequency-place function was calculated using the electrode position in the cochlea as obtained from postoperative skull radiographs. Individual frequency-place functions were compared to Greenwood's function in normal hearing. Electric stimulation elicited a low pitch in the apical region of the cochlea, and shifting the stimulating electrode towards the basal region elicited increasingly higher pitch. The frequency-place function did not show a significant shift relative to Greenwood's function. In cochlear implant patients with functional hearing in the non-implanted ear, electrical stimulation produced a frequency-place function that on average resembles Greenwood's function. These results differ from previously derived data.
  Hearing Research 10/2008; 245(1-2):98-106.