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Spectrogram

About: Spectrogram is a research topic. Over the lifetime, 5813 publications have been published within this topic receiving 81547 citations.


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Proceedings ArticleDOI
06 Sep 2012
TL;DR: By applying a sparse-representation based classifier to the device RSFs, state-of-the-art identification accuracy of 95.55% has been obtained on a set of 8 telephone handsets, from Lincoln-Labs Handset Database (LLHDB).
Abstract: Speech signals convey information not only for speakers' identity and the spoken language, but also for the acquisition devices used during their recording. Therefore, it is reasonable to perform acquisition device identification by analyzing the recorded speech signal. To this end, the random spectral features (RSFs) are proposed as an intrinsic fingerprint suitable for device identification. The RSFs are extracted from each speech signal by first averaging its spectrogram along the time axis and then by projecting the resulting mean spectrogram onto a Gaussian random matrix of compatible dimensions. By applying a sparse-representation based classifier to the device RSFs, state-of-the-art identification accuracy of 95.55% has been obtained on a set of 8 telephone handsets, from Lincoln-Labs Handset Database (LLHDB).

34 citations

Journal ArticleDOI
TL;DR: Window 95-based software, which processes the real time heart sound signal, has been developed and allows for both time varying amplitude graph and power spectral plot (based on 512-point fast Fourier transform (FFT)) to be shown simultaneously on a channel's view.
Abstract: A simple, low cost and non-invasive PC-based system that is capable to process real time fetal phonocardiographic signal has been built. The hardware of the system mainly consists of two modules: the front-end module and the data acquisition & control module. The front-end module is mainly used for heart sound signal capturing and conditioning. A new electronic stethoscope with enhanced performance that is non-intrusive, cost friendly and simple to implement has been built. The audio output unit enables the system to provide simultaneous listening and visual representation of the heart sound. The data acquisition & control module offers a four-channel analog multiplexer, a programmable gain amplifier, and a 12-bit resolution ADC. Various sampling rates can be provided through the programmable timer. Window 95-based software, which processes the real time heart sound signal, has been developed. The software written for the PCG allows for both time varying amplitude graph and power spectral plot (based on 512-point fast Fourier transform (FFT)) to be shown simultaneously on a channel's view. The simultaneous spectrograms gives a much better insight of the heart sounds characteristics than just the time-amplitude plot alone as in conventional PCG software. Using digital signal processing techniques, the power of the spectral plot is used to extract useful information of the heart sounds characteristics even in a situation where the heart sounds are among considerably loud background noises.

34 citations

Proceedings ArticleDOI
12 Oct 1998
TL;DR: Two output-based objective speech measures which are based on visual features of the spectrogram are proposed which achieve high correlation when used to predict subjective mean opinion scores (MOS) of real cellular telephone speech samples.
Abstract: In our previous papers, we studied many input-to-output objective speech quality measures, some of which achieved high correlation when used to predict subjective mean opinion scores (MOS) of real cellular telephone speech samples. Two problems of input-to-output measures are that the input must be available, which is almost never the case in the cellular telephone situation, and the input must be accurately synchronized with the output. Output-based measures which do not need the input are thus highly desirable. In this paper, we propose two output-based objective speech measures which are based on visual features of the spectrogram. In our experiment, one measure OBM achieves a correlation of 0.65 which is higher than most input-to-output measures and is close to the 0.73 achieved by the best input-to-output measure.

33 citations

Journal ArticleDOI
TL;DR: The design and FPGA implementation of sound encryption system based on a fractional-order chaotic system that is employed as a chaotic generator in a speech encryption algorithm and security analysis techniques are presented to show the robustness of the proposed algorithm.

33 citations

Proceedings ArticleDOI
01 Dec 2001
TL;DR: This paper identifies a hop free subset of data by discarding high-entropy spectral slices from the spectrogram, then performs low-rank decomposition of four-way data generated by capitalizing on both spatial and temporal shift invariance for high resolution direction of arrival (DOA) recovery.
Abstract: This paper considers the problem of blind localization and tracking of multiple frequency-hopped spread-spectrum (FHSS) signals using an antenna array, without knowledge of hopping patterns. We first identify a hop free subset of data by discarding high-entropy spectral slices from the spectrogram, then perform low-rank decomposition of four-way data generated by capitalizing on both spatial and temporal shift invariance for high resolution direction of arrival (DOA) recovery. After MMSE beamforming, a dynamic programming approach is developed for joint ML estimation of signal frequencies and hopping instants for signal user tracking.

33 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023627
20221,396
2021488
2020595
2019593