scholarly journals Estimating the operating point of the cochlear transducer using low-frequency biased distortion products

2009 ◽  
Vol 125 (4) ◽  
pp. 2129-2145 ◽  
Author(s):  
Daniel J. Brown ◽  
Jared J. Hartsock ◽  
Ruth M. Gill ◽  
Hillary E. Fitzgerald ◽  
Alec N. Salt
Keyword(s):  
Low Frequency ◽  
Operating Point ◽  
Distortion Products ◽  
Cochlear Transducer

Auditory Distortion Products Measured With Averaged Auditory Evoked Potentials

1992 ◽  
Vol 35 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Mark E. Chertoff ◽  
Kurt E. Hecox ◽  
Robert Goldstein
Keyword(s):  
High Frequency ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Low Frequency ◽  
Auditory Evoked Potential ◽  
Noise Floor ◽  
Distortion Products ◽  
Nonlinear Processing ◽  
Cochlear Damage ◽  
Primary Frequency

The purpose of this investigation was to describe the properties of averaged auditory evoked potential distortion products (AEP-DPs) in guinea pigs. This study provided a step toward developing a clinical index of nonlinear processing of auditory signals and supplied a baseline for studies evaluating the effect of cochlear damage on AEP-DPs. The amplitude of the AEP-DPs was evaluated as a function of f2/fl ratio (1.12–1.52) and primary frequency (500 Hz–2000 Hz). The amplitude of the AEP cubic difference tone (AEP-CDT) increased with increasing f2/fl ratio for the 500-Hz f1 primary and remained constant for the 800-Hz and 1700-Hz f1 primaries. The AEP-CDT generated by the 1100-Hz and 1400 Hz f1 primaries was maximum for the middle f2/fl ratios (1.22, 1.32, and 1.42). The AEP-CDT could not be distinguished from the noise floor for the 2000-Hz f1 primary. The AEP difference tone (AEP-DT) was larger and more frequently identified than the AEP-CDT. The amplitude of the AEP-DT decreased with an increase in f2/f1 ratio. The decrease was more pronounced for low-frequency f1 primaries than for high-frequency f1 primaries.

Sensitive Response to Low-Frequency Cochlear Distortion Products in the Auditory Midbrain

2009 ◽  
Vol 101 (3) ◽  
pp. 1560-1574 ◽  
Author(s):  
Cornelius Abel ◽  
Manfred Kössl
Keyword(s):  
Low Frequency ◽  
Otoacoustic Emission ◽  
Threshold Level ◽  
Auditory Midbrain ◽  
Low Frequencies ◽  
Distortion Product ◽  
Distortion Products ◽  
Third Phase ◽  
Complex Stimuli ◽  
Frequency Components

During auditory stimulation with several frequency components, distortion products (DPs) are generated as byproduct of nonlinear cochlear amplification. After generated, DP energy is reemitted into the ear channel where it can be measured as DP otoacoustic emission (DPOAE), and it also induces an excitatory response at cochlear places related to the DP frequencies. We measured responses of 91 inferior colliculus (IC) neurons in the gerbil during two-tone stimulation with frequencies well above the unit's receptive field but adequate to generate a distinct distortion product (f2-f1 or 2f1-f2) at the unit's characteristic frequency (CF). Neuronal responses to DPs could be accounted for by the simultaneously measured DPOAEs for DP frequencies >1.3 kHz. For DP frequencies <1.3 kHz ( n = 25), there was a discrepancy between intracochlear DP magnitude and DPOAE level, and most neurons responded as if the intracochlear DP level was significantly higher than the DPOAE level in the ear channel. In 12% of those low-frequency neurons, responses to the DPs could be elicited even if the stimulus tone levels were below the threshold level of the neuron at CF. High intracochlear f2-f1 and 2f1-f2 DP-levels were verified by cancellation of the neuronal DP response with a third phase-adjusted tone stimulus at the DP frequency. A frequency-specific reduction of middle ear gain at low frequencies is possibly involved in the reduction of DPOAE level. The results indicate that pitch-related properties of complex stimuli may be produced partially by high intracochlear f2-f1 distortion levels.

COCHLEAR TRANSDUCER OPERATING POINT ADAPTATION

2006 ◽  
Author(s):  
Y. ZOU ◽  
J. ZHENG ◽  
T. REN ◽  
A. L. NUTTALL
Keyword(s):  
Operating Point ◽  
Cochlear Transducer

High-Frequency Hearing Losses Caused by Low-Frequency Noises

1978 ◽  
Vol 86 (5) ◽  
pp. ORL-821-ORL-823 ◽  
Author(s):  
John H. Mills ◽  
Warren Y. Adkins ◽  
Robert M. Gilbert
Keyword(s):  
High Frequency ◽  
Human Subjects ◽  
Low Frequency ◽  
Wave Pattern ◽  
Travelling Wave ◽  
Center Frequency ◽  
Octave Band ◽  
Distortion Products ◽  
Band Noise ◽  
Cochlear Partition

Human subjects were exposed to an octave-band noise for 24 hours. Temporary threshold shifts increased for the first eight hours of exposure and then were asymptotic. While threshold shifts were largest at about one-half octave above the center frequency of the noise, a second maximum was observed at higher test frequencies. The exact frequency of this second maximum decreased from 7.0 kHz, for a noise centered at 2.0 kHz, to 5.5 kHz for a noise centered at 0.5 kHz. This result could be caused by the travelling wave pattern along the cochlear partition or to the production of distortion products.

Acceleration sound design for vehicles using distortion products

2021 ◽  
Vol 263 (4) ◽  
pp. 2494-2500
Author(s):  
Yu Aburagi ◽  
Natsuki Yamagiwa ◽  
Noriyuki Tanimoto ◽  
Shunsuke Ishimitsu ◽  
Mitsunori Matsumoto ◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Component ◽  
Second Step ◽  
Sound Design ◽  
Complex Sounds ◽  
Acoustic Design ◽  
Distortion Products ◽  
Order Components ◽  
The Relationship ◽  
Different Order

When considering the acoustic design of automobiles, low-frequency sounds can increase the excitement levels for users. However, there are several problems accompany an increase in the low-frequency levels of an engine sound. For example, it is difficult to create a balance between silence and excitement when a sound's different order components are changed. It is also difficult to generate heavy bass engine sounds in practical scenarios. Thus, the application of distortion products in the auditory system of the cochlea is considered. Distortion products are perceived when two or more sounds with slightly different frequencies are played simultaneously. This study was conducted to examine the possibility of achieving powerful engine sounds using distortion products. At first, the relationship between different combinations of complex sounds and the pitch perception of distortion products was investigated. As a second step, the application of distortion products to the acceleration sound was also considered. The results suggested the possibility of synthesizing a low-frequency component using distortion products inside a cochlea.

Constructing a cochlear transducer function from the summating potential using a low-frequency bias tone

2004 ◽  
Vol 116 (5) ◽  
pp. 2996-3007 ◽  
Author(s):  
Chul-Hee Choi ◽  
Mark E. Chertoff ◽  
Lin Bian ◽  
David Lerner
Keyword(s):  
Low Frequency ◽  
Summating Potential ◽  
Cochlear Transducer

A derivative-sigmoidal model reproduces operating point-dependent baroreflex neural arc transfer characteristics

2004 ◽  
Vol 286 (6) ◽  
pp. H2272-H2279 ◽  
Author(s):  
Toru Kawada ◽  
Kazunori Uemura ◽  
Koji Kashihara ◽  
Atsunori Kamiya ◽  
Masaru Sugimachi ◽  
...  
Keyword(s):  
Low Frequency ◽  
Systemic Circulation ◽  
Operating Point ◽  
Transfer Characteristics ◽  
Input Size ◽  
Bilateral Carotid ◽  
Sigmoidal Model ◽  
Derivative Filter ◽  
Noise Input ◽  
Sinus Pressure

A cascade model comprised of a derivative filter followed by a nonlinear sigmoidal component reproduces the input size dependence of transfer gain in the baroreflex neural arc from baroreceptor pressure input to efferent sympathetic nerve activity (SNA). We examined whether the same model could predict the operating point dependence of the baroreflex neural arc transfer characteristics estimated by a binary white noise input. In eight anesthetized rabbits, we isolated bilateral carotid sinuses from the systemic circulation and controlled intracarotid sinus pressure (CSP). We estimated the linear transfer function from CSP to SNA while varying mean CSP among 70, 100, 130, and 160 mmHg (P70, P100, P130, and P160, respectively). The transfer gain at 0.01 Hz was significantly smaller at P70 (0.61 ± 0.26) and P160 (0.60 ± 0.25) than at P100 (1.32 ± 0.42) and P130 (1.36 ± 0.45) (in arbitrary units/mmHg; means ± SD; P < 0.05). In contrast, transfer gain values above 0.5 Hz were similar among the protocols. As a result, the slope of increasing gain between 0.1 and 0.5 Hz was significantly steeper at P70 (17.6 ± 3.6) and P160 (14.1 ± 4.3) than at P100 (8.1 ± 4.4) and P130 (7.4 ± 6.6) (in dB/decade; means ± SD; P < 0.05). These results were consistent with those predicted by the derivative-sigmoidal model, where the deviation of mean input pressure from the center of the sigmoidal nonlinearity reduced the transfer gain mainly in the low-frequency range. The derivative-sigmoidal model functionally reproduces the dynamic SNA regulation by the arterial baroreflex over a wide operating range.

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