Localization of Two Noise Sources Overlapping in Time

1975 ◽  
Vol 18 (4) ◽  
pp. 663-671
Author(s):  
Willard R. Thurlow ◽  
Judith C. Jacques
Keyword(s):  
Wide Band ◽  
High Accuracy ◽  
Noise Sources ◽  
Band Noise ◽  
The Subject ◽  
Wide Band Noise

The accuracy of localization of two independent, wide-band noise sources, overlapping in time, was measured. Subjects given preliminary practice had little difficulty in localizing when sources separated by 55 degrees were located in front of them or in back of them, with one source 10 degrees from the midline. But when sources were at the side of the subject, perception that there were two sources present was poor if the sounds started only a few milliseconds apart; perception that there were two sources present tended to improve significantly as time between onset of the sounds was increased to 100 msec. Once a sound was perceived to be present, it was localized with fairly high accuracy.

Analysis of Evoked and Ongoing Electrical Activity at the Scalp of Human Subjects

1965 ◽  
Vol 8 (4) ◽  
pp. 371-387 ◽  
Author(s):  
Donald C. Teas
Keyword(s):  
Electrical Activity ◽  
Background Activity ◽  
Human Subjects ◽  
Low Frequency ◽  
Wide Band ◽  
Repeated Testing ◽  
Eyes Closed ◽  
Band Noise ◽  
The Subject ◽  
Wide Band Noise

Electrical activity at two locations on the scalp (Vertex and Vertex-3 cm, midline) for an experimental design suitable to clinical application, was recorded on magnetic tape. Data from 5 subjects with normal hearing, for 3 testing days, were processed. Average evoked responses to bursts of wide-band noise (30 dB and 50 dB SL) for two conditions (“eyes closed” and “reading”) were computed. The ongoing background activity was processed by computing its interval histogram. The percentage of ongoing activity within the frequency range 1.5 cps to 17 cps was extracted, and the magnitude of the N 1 -P 2 component of average responses was measured. These measures at the two electrode sites were analyzed by calculating analyses of variance for each of the four sets of data. Percentage of low-frequency background activity and N 1 -P 2 magnitude were positively related only for Day 1. A strong habituation effect appeared for Day 2 and Day 3. Habituation reduced differences between the two conditions and also differences between the two signal strengths for the average responses. Maximum N 1 -P 2 magnitude should be recorded for a single test with the subject relaxed and with his “eyes closed.” For repeated testing a discrimination between signals should be required to offset the attenuation of responses by habituation.

Discrimination of different temporal envelope structures of diotic and dichotic target signals within diotic wide-band noise

2005 ◽  
pp. 397-403 ◽  
Author(s):  
Steven van de Par ◽  
Armin Kohlrausch ◽  
Jeroen Breebaart ◽  
Martin McKinney
Keyword(s):  
Wide Band ◽  
Temporal Envelope ◽  
Band Noise ◽  
Wide Band Noise

On linear filtering under dependent wide-band noise

Stochastics ◽  
1988 ◽  
Vol 23 (4) ◽  
pp. 413-437 ◽  
Author(s):  
A. E. Bashirov
Keyword(s):  
Wide Band ◽  
Linear Filtering ◽  
Band Noise ◽  
Wide Band Noise

Stochastic Averaging of Strongly Nonlinear Oscillators Under Combined Harmonic and Wide-Band Noise Excitations

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Y. J. Wu ◽  
W. Q. Zhu
Keyword(s):  
Probability Density ◽  
Wide Band ◽  
Nonlinear Oscillators ◽  
Stochastic Averaging ◽  
Random Excitation ◽  
Stationary Response ◽  
Strongly Nonlinear ◽  
Band Noise ◽  
Wide Band Noise ◽  
Strongly Nonlinear Oscillators

Physical and engineering systems are often subjected to combined harmonic and random excitations. The random excitation is often modeled as Gaussian white noise for mathematical tractability. However, in practice, the random excitation is nonwhite. This paper investigates the stationary response probability density of strongly nonlinear oscillators under combined harmonic and wide-band noise excitations. By using generalized harmonic functions, a new stochastic averaging procedure for estimating stationary response probability density of strongly nonlinear oscillators under combined harmonic and wide-band noise excitations is developed. The damping can be linear and (or) nonlinear and the excitations can be external and (or) parametric. After stochastic averaging, the system state is represented by two-dimensional time-homogeneous diffusive Markov processes. The method of reduced Fokker–Planck–Kolmogorov equation is used to investigate the stationary response of the vibration system. A nonlinearly damped Duffing oscillator is taken as an example to show the application and validity of the method. In the case of primary external resonance, based on the stationary joint probability density of amplitude and phase difference, the stochastic jump of the Duffing oscillator and P-bifurcation as the system parameters change are examined for the first time. The agreement between the analytical results and those from Monte Carlo simulation of original system shows that the proposed procedure works quite well.

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