PatentDOI
Method and apparatus for measuring characteristics of a loudspeaker
Tsuneo Nitta,Masatoshi Tanaka +1 more
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TLDR
A loudspeaker and a microphone are arranged in a normal room, the loudspeaker being supplied with an impulse signal that is converted into a response signal by the microphone, and then Fourier-transformed.Abstract:
A loudspeaker and a microphone are arranged in a normal room, the loudspeaker being supplied with an impulse signal. A direct response sound from the loudspeaker and reflected sounds from wall surfaces in three directions of the normal room are converted into a response signal by the microphone. The response signal is A/D-converted, and then Fourier-transformed. The Fourier-transformed response signal is converted into a response signal with an absolute value, and then into a logarithmic response signal. The logarithmic response signal is filtered to eliminate signal components corresponding to the reflected sound. The filtered logarithmic response signal is A/D-converted, and supplied to a recorder.read more
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Method for determining transducer linear operational parameters
TL;DR: In this paper, an apparatus and method for determining a transducers principle operating parameters which utilizes two transfer functions, namely the transfer function from the pressure response (50) to the voltage drop across the transducer (60), and the transfer functions from the PSR to the current flow through the transducers(70), is presented.
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Method of processing geophysical data to compensate for earth filter attenuation
TL;DR: In this article, the received seismic traces were first compensated for the attenuation effects of the earth filter and the compensated seismic traces are then used to produce a close approximation of a zero-phase, band-limited output wavelet of the reflectivity of the geophysical formation under exploration.
PatentDOI
Automatic audiological analyzer
TL;DR: In this paper, an acoustical analyzer system analyzes the operating characteristics of an acoustic device by operator selection of frequencies and amplitudes of test tone signals, automatically generating test tone signal signals representative of the selected frequencies or amplitudes and driving the acoustic devices thereby to produce output signals from the device, sampling the output signals, generating sampled signals, applying Fast Fourier Transform analysis to the sampled signals to generate readout signal therefrom and operating readout means via the readout signals to display the operating characteristic of the device.
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Method of interpreting seismic data
TL;DR: In this article, the amplitude spectrum is cepstral windowed a first time to reduce the effects of nonwhite reflectivity upon the data, amortized at both low and high frequencies to approximate the analog wavelet.
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Sound field measuring apparatus and method
TL;DR: In this article, a sound field measuring apparatus has: an exponential pulse generator 11 which outputs a pulse signal to speakers 4 a, 4 b,... ; a microphone 6 which is disposed in an acoustic space 5 where the speakers are disposed, and a calculation section 15 which detects a time when the signal detected by the microphone 6 exceeds a predetermined threshold.
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Journal ArticleDOI
Homomorphic analysis of speech
Alan V. Oppenheim,R. Schafer +1 more
TL;DR: In this article, an approach to deconvolution of speech based on homomorphic superposition is discussed, which is suited to the separation of signals that have been convolved, and it can be seen as a generalization of the idea of algebraically linear transformations.
PatentDOI
Method and apparatus for cancelling room reverberation and noise pickup
TL;DR: In this paper, the authors used two microphones at the sound source and manipulated the signals of the two microphones to develop a single non-reverberant signal in the frequency domain.