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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Spectrogram</span></span>

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<div role="note" class="hatnote navigation-not-searchable">For the scientific instrument, see <a href="Optical_spectrograph" class="mw-redirect" title="Optical spectrograph">Optical spectrograph</a>.</div>

<p>A <b>spectrogram</b> is a visual representation of the <a href="Spectral_density" title="Spectral density">spectrum</a> of <a href="Frequencies" class="mw-redirect" title="Frequencies">frequencies</a> of a signal as it varies with time.

When applied to an <a href="Audio_signal" title="Audio signal">audio signal</a>, spectrograms are sometimes called <b>sonographs</b>, <b>voiceprints</b>, or <b>voicegrams</b>. When the data are represented in a 3D plot they may be called <i><a href="Waterfall_display" class="mw-redirect" title="Waterfall display">waterfall displays</a></i>.

</p><p>Spectrograms are used extensively in the fields of <a href="Music" title="Music">music</a>, <a href="Linguistics" title="Linguistics">linguistics</a>, <a href="Sonar" title="Sonar">sonar</a>, <a href="Radar" title="Radar">radar</a>, <a href="Speech_processing" title="Speech processing">speech processing</a>,<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> <a href="Seismology" title="Seismology">seismology</a>, <a href="Ornithology" title="Ornithology">ornithology</a>, and others. Spectrograms of audio can be used to identify spoken words <a href="Phonetics" title="Phonetics">phonetically</a>, and to analyse the <a href="Animal_communication" title="Animal communication">various calls of animals</a>.

</p><p>A spectrogram can be generated by an <a href="Optical_spectrometer" title="Optical spectrometer">optical spectrometer</a>, a bank of <a href="Band-pass_filter" title="Band-pass filter">band-pass filters</a>, by <a href="Fourier_transform" title="Fourier transform">Fourier transform</a> or by a <a href="Wavelet_transform" title="Wavelet transform">wavelet transform</a> (in which case it is also known as a <b>scaleogram</b> or <b>scalogram</b>).<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>

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<p>A spectrogram is usually depicted as a <a href="Heat_map" title="Heat map">heat map</a>, i.e., as an image with the intensity shown by varying the <a href="Colour" class="mw-redirect" title="Colour">colour</a> or <a href="Brightness" title="Brightness">brightness</a>.

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<div class="mw-heading mw-heading2"><h2 id="Format">Format</h2></div>

<p>A common format is a graph with two geometric dimensions: one axis represents <a href="Time" title="Time">time</a>, and the other axis represents <a href="Frequency" title="Frequency">frequency</a>; a third dimension indicating the <a href="Amplitude" title="Amplitude">amplitude</a> of a particular frequency at a particular time is represented by the <a href="Brightness" title="Brightness">intensity</a> or color of each point in the image.

</p><p>There are many variations of format: sometimes the vertical and horizontal axes are switched, so time runs up and down; sometimes as a <a href="Waterfall_plot" title="Waterfall plot">waterfall plot</a> where the amplitude is represented by height of a 3D surface instead of color or intensity. The frequency and amplitude axes can be either <a href="Linear" class="mw-redirect" title="Linear">linear</a> or <a href="Logarithm" title="Logarithm">logarithmic</a>, depending on what the graph is being used for. Audio would usually be represented with a logarithmic amplitude axis (probably in <a href="Decibel" title="Decibel">decibels</a>, or dB), and frequency would be linear to emphasize harmonic relationships, or logarithmic to emphasize musical, tonal relationships.

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<div class="gallerytext">Spectrogram of <a href="https://upload.wikimedia.org/wikipedia/commons/d/d1/Violin_for_spectrogram.ogg" class="internal external" title="Violin for spectrogram.ogg">this recording of a violin playing</a>. Note the harmonics occurring at whole-number multiples of the fundamental frequency.</div>

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<div class="gallerytext">3D surface spectrogram of a part from a music piece.</div>

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<div class="gallerytext">Spectrogram of a male voice saying 'ta ta ta'.</div>

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<div class="gallerytext">Spectrogram of dolphin vocalizations; chirps, clicks and harmonizing are visible as inverted Vs, vertical lines and horizontal striations respectively.</div>

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<div class="gallerytext">Spectrogram of an <a href="Frequency_modulation" title="Frequency modulation">FM</a> signal. In this case the signal <a href="Frequency" title="Frequency">frequency</a> is modulated with a <a href="Sinusoidal" class="mw-redirect" title="Sinusoidal">sinusoidal</a> frequency vs. time profile.</div>

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<div class="gallerytext">Spectrum above and waterfall (Spectrogram) below of an 8MHz wide <a href="PAL" title="PAL">PAL</a>-I Television signal.</div>

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<div class="gallerytext">Spectrogram of <a href="https://upload.wikimedia.org/wikipedia/commons/9/9c/Parus_major_15mars2011.ogg" class="internal external" title="Parus major 15mars2011.ogg">great tit song</a>.</div>

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<div class="gallerytext"><a href="Constant-Q_transform" title="Constant-Q transform">Constant-Q</a> spectrogram of a gravitational wave (<a href="GW170817" title="GW170817">GW170817</a>).</div>

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<div class="gallerytext">Spectrogram and waterfalls of 3 whistled notes.</div>

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<div class="gallerytext">Spectrogram of the <a href="Soundscape_ecology" title="Soundscape ecology">soundscape ecology</a> of <a href="Mount_Rainier_National_Park" title="Mount Rainier National Park">Mount Rainier National Park</a>, with the sounds of different creatures and aircraft highlighted</div>

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<div class="gallerytext">Spectrogram (generated with the freeware <a rel="nofollow" class="external text" href="https://github.com/Christoph-Lauer/Sonogram-Visible-Speech">Sonogram visible Speech</a>).</div>

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<div class="gallerytext"><a href="Variable-Q_transform" class="mw-redirect" title="Variable-Q transform">Variable-Q transform</a> spectrogram of a piano chord (generated using <a href="FFmpeg" title="FFmpeg">FFmpeg</a>'s showcqt filter).</div>

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<div class="mw-heading mw-heading2"><h2 id="Generation">Generation</h2></div>

<p>Spectrograms of light may be created directly using an <a href="Optical_spectrometer" title="Optical spectrometer">optical spectrometer</a> over time.

</p><p>Spectrograms may be created from a <a href="Time-domain" class="mw-redirect" title="Time-domain">time-domain</a> signal in one of two ways: approximated as a filterbank that results from a series of <a href="Band-pass_filter" title="Band-pass filter">band-pass filters</a> (this was the only way before the advent of modern digital signal processing), or calculated from the time signal using the <a href="Fourier_transform" title="Fourier transform">Fourier transform</a>. These two methods actually form two different <a href="Time%E2%80%93frequency_representation" title="Time–frequency representation">time–frequency representations</a>, but are equivalent under some conditions.

</p><p>The bandpass filters method usually uses <a href="Analog_signal" title="Analog signal">analog</a> processing to divide the input signal into frequency bands; the magnitude of each filter's output controls a transducer that records the spectrogram as an image on paper.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>

</p><p>Creating a spectrogram using the FFT is a <a href="Digital_signal_processing" title="Digital signal processing">digital process</a>. Digitally <a href="Sampling_(signal_processing)" title="Sampling (signal processing)">sampled</a> data, in the <a href="Time_series" title="Time series">time domain</a>, is broken up into chunks, which usually overlap, and Fourier transformed to calculate the magnitude of the frequency spectrum for each chunk. Each chunk then corresponds to a vertical line in the image; a measurement of magnitude versus frequency for a specific moment in time (the midpoint of the chunk). These spectrums or time plots are then "laid side by side" to form the image or a three-dimensional surface,<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> or slightly overlapped in various ways, i.e. <a href="Window_function#Overlapping_windows" title="Window function">windowing</a>. This process essentially corresponds to computing the squared <a href="Magnitude_(mathematics)" title="Magnitude (mathematics)">magnitude</a> of the <a href="Short-time_Fourier_transform" title="Short-time Fourier transform">short-time Fourier transform</a> (STFT) of the signal <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle s(t)}">

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<annotation encoding="application/x-tex">{\displaystyle s(t)}</annotation>

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</math></span><img src="./c484de351ba40ccb9a5ad522c29c1aac5686c0df.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:3.739ex; height:2.843ex;" alt="{\displaystyle s(t)}" loading="lazy"></span> — that is, for a window width <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \omega }">

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<annotation encoding="application/x-tex">{\displaystyle \omega }</annotation>

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</math></span><img src="./48eff443f9de7a985bb94ca3bde20813ea737be8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.446ex; height:1.676ex;" alt="{\displaystyle \omega }" loading="lazy"></span>, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mathrm {spectrogram} (t,\omega )=\left|\mathrm {STFT} (t,\omega )\right|^{2}}">

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<annotation encoding="application/x-tex">{\displaystyle \mathrm {spectrogram} (t,\omega )=\left|\mathrm {STFT} (t,\omega )\right|^{2}}</annotation>

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</math></span><img src="./ef3a0f202b69189d93454a2373182f6f0d926992.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:34.295ex; height:3.343ex;" alt="{\displaystyle \mathrm {spectrogram} (t,\omega )=\left|\mathrm {STFT} (t,\omega )\right|^{2}}" loading="lazy"></span>.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

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<div class="mw-heading mw-heading2"><h2 id="Limitations_and_resynthesis">Limitations and resynthesis</h2></div>

<p>From the formula above, it appears that a spectrogram contains no information about the exact, or even approximate, <a href="Phase_(waves)" title="Phase (waves)">phase</a> of the signal that it represents. For this reason, it is not possible to reverse the process and generate a copy of the original signal from a spectrogram, though in situations where the exact initial phase is unimportant it may be possible to generate a useful approximation of the original signal. The Analysis & Resynthesis Sound Spectrograph<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> is an example of a computer program that attempts to do this. The <a href="Pattern_playback" title="Pattern playback">pattern playback</a> was an early speech synthesizer, designed at <a href="Haskins_Laboratories" title="Haskins Laboratories">Haskins Laboratories</a> in the late 1940s, that converted pictures of the acoustic patterns of speech (spectrograms) back into sound.

</p><p>In fact, there is some phase information in the spectrogram, but it appears in another form, as time delay (or <a href="Group_delay" class="mw-redirect" title="Group delay">group delay</a>) which is the <a href="Dual_(mathematics)" class="mw-redirect" title="Dual (mathematics)">dual</a> of the <a href="Instantaneous_frequency" class="mw-redirect" title="Instantaneous frequency">instantaneous frequency</a>.<sup id="cite_ref-Boashash1992_7-0" class="reference"><a href="#cite_note-Boashash1992-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>

</p><p>The size and shape of the analysis window can be varied. A smaller (shorter) window will produce more accurate results in timing, at the expense of precision of frequency representation. A larger (longer) window will provide a more precise frequency representation, at the expense of precision in timing representation. This is an instance of the <a href="Heisenberg_uncertainty_principle" class="mw-redirect" title="Heisenberg uncertainty principle">Heisenberg uncertainty principle</a>, that the product of the precision in two <a href="Conjugate_variables" title="Conjugate variables">conjugate variables</a> is greater than or equal to a constant (B*T>=1 in the usual notation).<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

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<div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2></div>

<ul><li>Early analog spectrograms were applied to a wide range of areas including the study of bird calls (such as that of the <a href="Great_tit" title="Great tit">great tit</a>), with current research continuing using modern digital equipment<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> and applied to all animal sounds. Contemporary use of the digital spectrogram is especially useful for studying <a href="Frequency_modulation" title="Frequency modulation">frequency modulation</a> (FM) in animal calls. Specifically, the distinguishing characteristics of FM chirps, broadband <a href="Clicking_noise" class="mw-redirect" title="Clicking noise">clicks</a>, and social harmonizing are most easily visualized with the spectrogram.</li>

<li>Spectrograms are useful in assisting in overcoming speech deficits and in speech training for the portion of the population that is profoundly <a href="Hearing_impairment" class="mw-redirect" title="Hearing impairment">deaf</a>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup></li>

<li>The studies of <a href="Phonetics" title="Phonetics">phonetics</a> and <a href="Speech_synthesis" title="Speech synthesis">speech synthesis</a> are often facilitated through the use of spectrograms.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup></li>

<li>In deep learning-keyed speech synthesis, spectrogram (or spectrogram in <a href="Mel_scale" title="Mel scale">mel scale</a>) is first predicted by a seq2seq model, then the spectrogram is fed to a neural vocoder to derive the synthesized raw waveform.</li>

<li>By reversing the process of producing a spectrogram, it is possible to create a signal whose spectrogram is an arbitrary image. This technique can be used to hide a picture in a piece of audio and has been employed by several <a href="Electronic_music" title="Electronic music">electronic music</a> artists.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> See also <a href="Steganography" title="Steganography">Steganography</a>.</li>

<li>Some modern music is created using spectrograms as an intermediate medium; changing the intensity of different frequencies over time, or even creating new ones, by drawing them and then inverse transforming. See <a href="Audio_timescale-pitch_modification" class="mw-redirect" title="Audio timescale-pitch modification">Audio timescale-pitch modification</a> and <a href="Phase_vocoder" title="Phase vocoder">Phase vocoder</a>.</li>

<li>Spectrograms can be used to analyze the results of passing a test signal through a signal processor such as a filter in order to check its performance.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup></li>

<li>High definition spectrograms are used in the development of RF and microwave systems.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup></li>

<li>Spectrograms are now used to display <a href="Scattering_parameters" title="Scattering parameters">scattering parameters</a> measured with vector network analyzers.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup></li>

<li>The <a href="United_States_Geological_Survey" title="United States Geological Survey">US Geological Survey</a> and the <a href="IRIS_Consortium" title="IRIS Consortium">IRIS Consortium</a> provide near real-time spectrogram displays for monitoring seismic stations.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup></li>

<li>Spectrograms can be used with <a href="Recurrent_neural_network" title="Recurrent neural network">recurrent neural networks</a> for <a href="Speech_recognition" title="Speech recognition">speech recognition</a>.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup></li>

<li>Individuals' spectrograms are collected by the <a href="Government_of_China" title="Government of China">Chinese government</a> as part of its <a href="Mass_surveillance_in_China" title="Mass surveillance in China">mass surveillance</a> programs.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup></li>

<li>For a vibration signal, a spectrogram's color scale identifies the frequencies of a waveform's amplitude peaks over time. Unlike a time or frequency graph, a spectrogram correlates peak values to time and frequency. Vibration test engineers use spectrograms to analyze the frequency content of a continuous waveform, locating strong signals and determining how the vibration behavior changes over time.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup></li>

<li>Spectrograms can be used to analyze speech in two different applications: automatic detection of speech deficits in cochlear implant users and phoneme class recognition to extract phone-attribute features.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup></li>

<li>In order to obtain a speaker's pronunciation characteristics, some researchers proposed a method based on an idea from bionics, which uses spectrogram statistics to achieve a characteristic spectrogram to give a stable representation of the speaker's pronunciation from a linear superposition of short-time spectrograms.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup></li>

<li>Researchers explore a novel approach to ECG signal analysis by leveraging spectrogram techniques, possibly for enhanced visualization and understanding. The integration of MFCC for feature extraction suggests a cross-disciplinary application, borrowing methods from audio processing to extract relevant information from biomedical signals.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup></li>

<li>Accurate interpretation of temperature indicating paint (TIP) is of great importance in aviation and other industrial applications. 2D spectrogram of TIP can be used in temperature interpretation.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup></li>

<li>The spectrogram can be used to process the signal for the rate of change of the human thorax. By visualizing respiratory signals using a spectrogram, the researchers have proposed an approach to the classification of respiration states based on a neural network model.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup></li></ul>

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<ul><li><a href="Acoustic_signature" title="Acoustic signature">Acoustic signature</a></li>

<li><a href="Chromagram" class="mw-redirect" title="Chromagram">Chromagram</a></li>

<li><a href="Fourier_analysis" title="Fourier analysis">Fourier analysis</a> for computing periodicity in evenly spaced data</li>

<li><a href="Generalized_spectrogram" title="Generalized spectrogram">Generalized spectrogram</a></li>

<li><a href="Least-squares_spectral_analysis" title="Least-squares spectral analysis">Least-squares spectral analysis</a> for computing periodicity in unevenly spaced data</li>

<li><a href="List_of_unexplained_sounds" title="List of unexplained sounds">List of unexplained sounds</a></li>

<li><a href="Reassignment_method" title="Reassignment method">Reassignment method</a></li>

<li><a href="Spectral_music" title="Spectral music">Spectral music</a></li>

<li><a href="Spectrometer" title="Spectrometer">Spectrometer</a></li>

<li><a href="Strobe_tuner" class="mw-redirect" title="Strobe tuner">Strobe tuner</a></li>

<li><a href="Waveform" title="Waveform">Waveform</a></li></ul>

</div>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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<li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text">JL Flanagan, Speech Analysis, Synthesis and Perception, Springer- Verlag, New York, 1972</span>

</li>

/* start https://en.wikipedia.org/ */

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</style><cite id="CITEREFSejdicDjurovicStankovic2008" class="citation journal cs1">Sejdic, E.; Djurovic, I.; Stankovic, L. (August 2008). "Quantitative Performance Analysis of Scalogram as Instantaneous Frequency Estimator". <i>IEEE Transactions on Signal Processing</i>. <b>56</b> (8): <span class="nowrap">3837–</span>3845. <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2008ITSP...56.3837S">2008ITSP...56.3837S</a>. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FTSP.2008.924856">10.1109/TSP.2008.924856</a>. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1053-587X">1053-587X</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:16396084">16396084</a>.</cite></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.sfu.ca/sonic-studio/handbook/Spectrograph.html">"Spectrograph"</a>. <i>www.sfu.ca</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://ccrma.stanford.edu/~jos/mdft/Spectrograms.html">"Spectrograms"</a>. <i>ccrma.stanford.edu</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://zone.ni.com/reference/en-XX/help/371361E-01/lvanls/stft_spectrogram_core/#details">"STFT Spectrograms VI – NI LabVIEW 8.6 Help"</a>. <i>zone.ni.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://arss.sourceforge.net">"The Analysis & Resynthesis Sound Spectrograph"</a>. <i>arss.sourceforge.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-Boashash1992-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-Boashash1992_7-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFBoashash1992" class="citation journal cs1">Boashash, B. (1992). "Estimating and interpreting the instantaneous frequency of a signal. I. Fundamentals". <i>Proceedings of the IEEE</i>. <b>80</b> (4). Institute of Electrical and Electronics Engineers (IEEE): <span class="nowrap">520–</span>538. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2F5.135376">10.1109/5.135376</a>. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0018-9219">0018-9219</a>.</cite></span>

</li>

<li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190125182117/http://fourier.eng.hmc.edu/e161/lectures/fourier/node2.html">"Heisenberg Uncertainty Principle"</a>. Archived from <a rel="nofollow" class="external text" href="http://fourier.eng.hmc.edu/e161/lectures/fourier/node2.html">the original</a> on 2019-01-25<span class="reference-accessdate">. Retrieved <span class="nowrap">2019-02-05</span></span>.</cite></span>

</li>

<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.birdsongs.it/index.asp">"BIRD SONGS AND CALLS WITH SPECTROGRAMS ( SONOGRAMS ) OF SOUTHERN TUSCANY ( Toscana – Italy )"</a>. <i>www.birdsongs.it</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><cite id="CITEREFSaundersHillFranklin1981" class="citation journal cs1">Saunders, Frank A.; Hill, William A.; Franklin, Barbara (1 December 1981). "A wearable tactile sensory aid for profoundly deaf children". <i>Journal of Medical Systems</i>. <b>5</b> (4): <span class="nowrap">265–</span>270. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2FBF02222144">10.1007/BF02222144</a>. <a href="PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/7320662">7320662</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:26620843">26620843</a>.</cite></span>

</li>

<li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/19990427185722/http://cslu.cse.ogi.edu/tutordemos/SpectrogramReading/spectrogram_reading.html">"Spectrogram Reading"</a>. <i>ogi.edu</i>. Archived from <a rel="nofollow" class="external text" href="http://cslu.cse.ogi.edu/tutordemos/SpectrogramReading/spectrogram_reading.html">the original</a> on 27 April 1999<span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.fon.hum.uva.nl/praat/">"Praat: doing Phonetics by Computer"</a>. <i>www.fon.hum.uva.nl</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.bastwood.com/aphex.php">"The Aphex Face – bastwood"</a>. <i>www.bastwood.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://src.infinitewave.ca">"SRC Comparisons"</a>. <i>src.infinitewave.ca</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.constantwave.com/gallery.aspx">"constantwave.com – constantwave Resources and Information"</a>. <i>www.constantwave.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120810020043/http://www.constantwave.com/spectro_vna.aspx">"Spectrograms for vector network analyzers"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.constantwave.com/spectro_vna.aspx">the original</a> on 2012-08-10.</cite></span>

</li>

<li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://earthquake.usgs.gov/monitoring/spectrograms/24hr/">"Real-time Spectrogram Displays"</a>. <i>earthquake.usgs.gov</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://service.iris.edu/mustang/noise-spectrogram/docs/1/help/">"IRIS: MUSTANG: Noise-Spectrogram: Docs: v. 1: Help"</a>.</cite></span>

</li>

<li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><cite id="CITEREFGeitgey2016" class="citation web cs1">Geitgey, Adam (2016-12-24). <a rel="nofollow" class="external text" href="https://medium.com/@ageitgey/machine-learning-is-fun-part-6-how-to-do-speech-recognition-with-deep-learning-28293c162f7a">"Machine Learning is Fun Part 6: How to do Speech Recognition with Deep Learning"</a>. <i>Medium</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2018-03-21</span></span>.</cite></span>

</li>

<li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text">See also <a href="Praat" title="Praat">Praat</a>.</span>

</li>

<li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><cite class="citation news cs1"><span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.economist.com/china/2023/11/23/chinas-enormous-surveillance-state-is-still-growing">"China's enormous surveillance state is still growing"</a></span>. <i><a href="The_Economist" title="The Economist">The Economist</a></i>. November 23, 2023. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0013-0613">0013-0613</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-11-25</span></span>.</cite></span>

</li>

<li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://vibrationresearch.com/blog/what-is-a-spectrogram/">"What is a Spectrogram?"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-12-18</span></span>.</cite></span>

</li>

<li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><cite id="CITEREFT.P.J._C.E.2021" class="citation journal cs1">T., Arias-Vergara; P., Klumpp; J. C., Vasquez-Correa; E., Nöth; J. R., Orozco-Arroyave; M., Schuster (2021). <a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs10044-020-00921-5">"Multi-channel spectrograms for speech processing applications using deep learning methods"</a>. <i>Pattern Analysis and Applications</i>. <b>24</b> (2): <span class="nowrap">423–</span>431. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs10044-020-00921-5">10.1007/s10044-020-00921-5</a></span>.</cite></span>

</li>

<li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><cite id="CITEREFJiaChenYuWang2021" class="citation journal cs1">Jia, Yanjie; Chen, Xi; Yu, Jieqiong; Wang, Lianming; Xu, Yuanzhe; Liu, Shaojin; Wang, Yonghui (2021). <a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs40747-020-00172-1">"Speaker recognition based on characteristic spectrograms and an improved self-organizing feature map neural network"</a>. <i>Complex & Intelligent Systems</i>. <b>7</b> (4): <span class="nowrap">1749–</span>1757. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs40747-020-00172-1">10.1007/s40747-020-00172-1</a></span>.</cite></span>

</li>

<li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><cite id="CITEREFYalamanchiliMadhumathiBalaji2022" class="citation journal cs1">Yalamanchili, Arpitha; Madhumathi, G. L.; Balaji, N. (2022). <span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://link.springer.com/article/10.1007/s12652-021-02926-2">"Spectrogram analysis of ECG signal and classification efficiency using MFCC feature extraction technique"</a></span>. <i>Journal of Ambient Intelligence and Humanized Computing</i>. <b>13</b> (2): <span class="nowrap">757–</span>767. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs12652-021-02926-2">10.1007/s12652-021-02926-2</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:233657057">233657057</a>.</cite></span>

</li>

<li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><cite id="CITEREFGeWangGuiYe2023" class="citation journal cs1">Ge, Junfeng; Wang, Li; Gui, Kang; Ye, Lin (30 September 2023). <span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.sciencedirect.com/science/article/pii/S0263224123008813">"Temperature interpretation method for temperature indicating paint based on spectrogram"</a></span>. <i>Measurement</i>. <b>219</b>. <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2023Meas..21913317G">2023Meas..21913317G</a>. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.measurement.2023.113317">10.1016/j.measurement.2023.113317</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:259871198">259871198</a>.</cite></span>

</li>

<li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><cite id="CITEREFParkLee2022" class="citation journal cs1">Park, Cheolhyeong; Lee, Deokwoo (11 February 2022). <a rel="nofollow" class="external text" href="https://doi.org/10.3390%2Fapp12041895">"Classification of Respiratory States Using Spectrogram with Convolutional Neural Network"</a>. <i>Applied Sciences</i>. <b>12</b> (4): 1895. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.3390%2Fapp12041895">10.3390/app12041895</a></span>.</cite></span>

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<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

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<div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Spectrograms" class="extiw external" title="commons:Category:Spectrograms">Spectrograms</a></span>.</div></div>

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<div class="side-box-text plainlist">Look up <i><b><a href="https://en.wiktionary.org/wiki/Special:Search/spectrogram" class="extiw external" title="wiktionary:Special:Search/spectrogram">spectrogram</a></b></i> in Wiktionary, the free dictionary.</div></div>

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<ul><li><a rel="nofollow" class="external text" href="https://auditoryneuroscience.com/acoustics/spectrogram">See an online spectrogram of speech or other sounds captured by your computer's microphone.</a></li>

<li><a rel="nofollow" class="external text" href="http://www.audiocheck.net/audiocheck_spectrotyper.php">Generating a tone sequence whose spectrogram matches an arbitrary text, online</a></li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110725231858/http://devrand.org/show_item.html?item=64&page=Project">Further information on creating a signal whose spectrogram is an arbitrary image</a></li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120331164713/https://kdenlive.org/users/granjow/introducing-scopes-audio-spectrum-and-spectrogram">Article describing the development of a software spectrogram</a></li>

<li><a rel="nofollow" class="external text" href="http://www.spectrogramsforspeech.com/background/history-of-spectrograms/">History of spectrograms & development of instrumentation</a></li>

<li><a rel="nofollow" class="external text" href="http://home.cc.umanitoba.ca/~robh/howto.html">How to identify the words in a spectrogram</a> from a linguistic professor's <i>Monthly Mystery Spectrogram</i> publication.</li>

<li><a rel="nofollow" class="external text" href="https://github.com/Christoph-Lauer/Sonogram">Sonogram Visible Speech</a> GPL Licensed freeware for the Spectrogram generation of Signal Files.</li></ul></div><div><div class="zim-footer">

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