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Cepstrum

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172: 2073:. For example, if the sampling rate of an audio signal is 44100 Hz and there is a large peak in the cepstrum whose quefrency is 100 samples, the peak indicates the presence of a fundamental frequency that is 44100/100 = 441 Hz. This peak occurs in the cepstrum because the harmonics in the spectrum are periodic and the period corresponds to the fundamental frequency, since harmonics are integer multiples of the fundamental frequency. 2080:, which stands for "Kolmogorov-equation power-series time response", is similar to the cepstrum and has the same relation to it as expected value has to statistical average, i.e. cepstrum is the empirically measured quantity, while kepstrum is the theoretical quantity. It was in use before the cepstrum. 207:
References to the Bogert paper, in a bibliography, are often edited incorrectly. The terms "quefrency", "alanysis", "cepstrum" and "saphe" were invented by the authors by rearranging the letters in frequency, analysis, spectrum, and phase. The invented terms are defined in analogy to the older terms.
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Note that a pure sine wave can not be used to test the cepstrum for its pitch determination from quefrency as a pure sine wave does not contain any harmonics and does not lead to quefrency peaks. Rather, a test signal containing harmonics should be used (such as the sum of at least two sines where
2137:(such as a source and filter) into sums of their cepstra, for linear separation. In particular, the power cepstrum is often used as a feature vector for representing the human voice and musical signals. For these applications, the spectrum is usually first transformed using the 1810: 734: 863: 2290:
signal, from the power spectrum of the sEMG signal itself. In this way, only information about the motor unit action potential (MUAP) shape and amplitude was maintained, which was then used to estimate the parameters of a time-domain model of the MUAP itself.
1066: 1173: 872:. It can be shown that both formulas are consistent with each other as the frequency spectral distribution remains the same, the only difference being a scaling factor which can be applied afterwards. Some articles prefer the second formula. 2036:
Main application is the modification of the signal in the quefrency domain (liftering) as an analog operation to filtering in the spectral frequency domain. An example is the suppression of echo effects by suppression of certain quefrencies.
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G. Biagetti, P. Crippa, S. Orcioni, and C. Turchetti, “Homomorphic deconvolution for muap estimation from surface emg signals,” IEEE Journal of Biomedical and Health Informatics, vol. 21, no. 2, pp. 328– 338, March
952: 2256: 1650: 609: 748: 2098:. It can be implemented by multiplying by a window in the quefrency domain and then converting back to the frequency domain, resulting in a modified signal, i.e. with signal echo being reduced. 2598:"A kepstrum approach to filtering, smoothing and prediction with application to speech enhancement", T. J. Moir and J. F. Barrett, Proc. Royal Society A, vol. 459, 2003, pp. 2957–2976. 1271: 2493: 963: 410: 2173:
the second sine is some harmonic (multiple) of the first sine, or better, a signal with a square or triangle waveform, as such signals provide many overtones in the spectrum.).
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A. Michael Noll (1964), “Short-Time Spectrum and Cepstrum Techniques for Vocal-Pitch Detection”, Journal of the Acoustical Society of America, Vol. 36, No. 2, pp. 296–302.
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The complex cepstrum retains the information about the phase. Thus it is always possible to return from the quefrency domain to the time domain by the inverse operation:
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Recently, cepstrum-based deconvolution was used on surface electromyography signals, to remove the effect of the stochastic impulse train, which originates an
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The cepstrum can be seen as information about the rate of change in the different spectrum bands. It was originally invented for characterizing the seismic
1413: 2587:"Predictive decomposition of time series with applications to seismic exploration", E. A. Robinson MIT report 1954; Geophysics 1967 vol. 32, pp. 418–484; 875:
Other notations are possible due to the fact that the log of the power spectrum is equal to the log of the spectrum if a scaling factor 2 is applied:
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as a product of magnitude and phase, and subsequently as a sum. Further simplification is obvious, if log is a natural logarithm with base 
2589:"Use of the kepstrum in signal analysis", M. T. Silvia and E. A. Robinson, Geoexploration, volume 16, issues 1–2, April 1978, pages 55–73. 2287: 881: 739:
The power cepstrum has main applications in analysis of sound and vibration signals. It is a complementary tool to spectral analysis.
1805:{\displaystyle \log _{e}({\mathcal {F}})=\log _{e}({\mathcal {|F|}})+\log _{e}(e^{i\varphi })=\log _{e}({\mathcal {|F|}})+i\varphi } 2760: 2610:
A. Michael Noll (1967), “Cepstrum Pitch Determination”, Journal of the Acoustical Society of America, Vol. 41, No. 2, pp. 293–309.
729:{\displaystyle C_{p}=\left|{\mathcal {F}}^{-1}\left\{\log \left(\left|{\mathcal {F}}\{f(t)\}\right|^{2}\right)\right\}\right|^{2}} 2122:
signal returns. Cepstrum pitch determination is particularly effective because the effects of the vocal excitation (pitch) and
188:. It serves as a tool to investigate periodic structures in frequency spectra. Such effects are related to noticeable echos or 858:{\displaystyle C_{p}=\left|{\mathcal {F}}\left\{\log \left(\left|{\mathcal {F}}\{f(t)\}\right|^{2}\right)\right\}\right|^{2}} 1407:
was defined by Oppenheim in his development of homomorphic system theory. The formula is provided also in other literature.
2633:, "Short-Time 'Cepstrum' Pitch Detection," (abstract) Journal of the Acoustical Society of America, Vol. 36, No. 5, p. 1030 2145:
or MFC (its coefficients are called mel-frequency cepstral coefficients, or MFCCs). It is used for voice identification,
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and much more. The cepstrum is useful in these applications because the low-frequency periodic excitation from the
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A. V. Oppenheim, "Superposition in a class of nonlinear systems" Ph.D. diss., Res. Lab. Electronics, M.I.T. 1965.
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R.B. Randall: Cepstrum Analysis and Gearbox Fault Diagnosis, Brüel&Kjaer Application Notes 233-80, Edition 2
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Oppenheim, A.V.; Schafer, R.W. (2004). "Dsp history - From frequency to quefrency: a history of the cepstrum".
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It is derived from the complex cepstrum (defined below) by discarding the phase information (contained in the
2566: 1225: 1061:{\displaystyle C_{p}=\left|{\mathcal {F}}^{-1}\left\{2\log |{\mathcal {F}}|\right\}\right|^{2},{\text{ or}}} 363: 237:
transformation to frequency domain, where the final independent variable, the quefrency, has a time scale.
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explosions. It has also been used to determine the fundamental frequency of human speech and to analyze
523: 2781: 367: 1168:{\displaystyle C_{p}=4\cdot \left|{\mathcal {F}}^{-1}\left\{\log |{\mathcal {F}}|\right\}\right|^{2},} 2511:
Taschenbuch der Informatik – Band III – Anwendungen und spezielle Systeme der Nachrichtenverarbeitung
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Further, it shall be noted, that the final squaring operation in the formula for the power spectrum
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complex cepstrum: The logarithm is taken from the spectrum, which is calculated via Fourier analysis
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Beckhoff information system: TF3600 TC3 Condition Monitoring: Gearbox monitoring (online, 4.4.2020)
2327:] of Time Series for Echoes: Cepstrum, Pseudo Autocovariance, Cross-Cepstrum and Saphe Cracking 2282:
machine vibration analysis based on harmonic patterns (gearbox faults, turbine blade failures, ...)
1388:{\displaystyle C_{r}={\mathcal {F}}^{-1}\left\{\log({\mathcal {|{\mathcal {F}}\{f(t)\}|}})\right\}} 2410: 2019:{\displaystyle f(t)={\mathcal {F}}^{-1}\left\{b^{\left({\mathcal {F}}\{C_{c}\}\right)}\right\},} 2142: 463:
depends on the user. In some articles the base is not specified, others prefer base 10 or 
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Childers, D.G.; Skinner, D.P.; Kemerait, R.C. (1977). "The cepstrum: A guide to processing".
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Playing further on the anagram theme, a filter that operates on a cepstrum might be called a
1913:{\displaystyle C_{c}={\mathcal {F}}^{-1}\left\{\log _{e}({\mathcal {|F|}})+i\varphi \right\}} 421: 2710: 2665: 2630: 2295: 2087:. The autocepstrum is more accurate than the cepstrum in the analysis of data with echoes. 1188: 189: 2496:, (PDF) in: Mechanical Systems and Signal Processing, Volume 97, December 2017 (Elsevier). 2126:(formants) are additive in the logarithm of the power spectrum and thus clearly separate. 467:. The choice of the base has no impact on the basic calculation rules, but sometimes base 275: 8: 513: 2714: 2669: 2734: 2689: 2540: 2461: 310: 20: 2753: 2726: 2681: 2528: 2518: 2506: 2375: 2107: 1281: 359: 184:
The concept of the cepstrum was introduced in 1963 by B. P. Bogert, M. J. Healy, and
1497:{\displaystyle C_{c}={\mathcal {F}}^{-1}\left\{\log({\mathcal {F}}\{f(t)\})\right\}} 2738: 2718: 2693: 2673: 2166: 2095: 229: 37: 27: 2483:
A. V. Oppenheim, R. W. Schafer, "Digital Signal Processing", 1975 (Prentice Hall).
2514: 2369: 2084: 2069:. The quefrency is a measure of time, though not in the sense of a signal in the 557: 122: 2270:
dealing with reflection inference (radar, sonar applications, earth seismology)
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and Noll in the 1960s for application to pitch determination of human speech.
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medical applications in analysis of electroencephalogram (EEG) and brain waves
1639:{\displaystyle \log({\mathcal {F}})=\log({\mathcal {|F|\cdot e^{i\varphi }}})} 257:
The following abbreviations are used in the formulas to explain the cepstrum:
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The cepstrum is the result of following sequence of mathematical operations:
201: 2677: 2433: 2664:(10). Institute of Electrical and Electronics Engineers (IEEE): 1428–1443. 2494:"A history of cepstrum analysis and its application to mechanical problems" 171: 134: 2180:
of two signals can be expressed as the addition of their complex cepstra:
1284:). It has a focus on periodic effects in the amplitudes of the spectrum: 2177: 2162: 2158: 2134: 2123: 2070: 371: 225: 185: 2052:
phase spectrum = (complex cepstrum − time reversal of complex cepstrum).
2709:(5). Institute of Electrical and Electronics Engineers (IEEE): 95–106. 2150: 2111: 2138: 452: 197: 126: 118: 2367: 2169:, are additive and in different regions in the quefrency domain. 2154: 1212:
is sometimes called unnecessary and therefore sometimes omitted.
2532: 947:{\displaystyle \log |{\mathcal {F}}|^{2}=2\log |{\mathcal {F}}|} 250:
power cepstrum: The logarithm is taken from the "power spectrum"
125:. The method is a tool for investigating periodic structures in 2462:"Real cepstrum and minimum-phase reconstruction - MATLAB rceps" 2333:(M. Rosenblatt, Ed) Chapter 15, 209-243. New York: Wiley, 1963. 868:
Due to this formula, the cepstrum is also sometimes called the
221: 19:"Cepstral" redirects here. For the text-to-speech company, see 2266:
The concept of the cepstrum has led to numerous applications:
1883: 1780: 1706: 1607: 1361: 1355: 512:, which is calculated from real- and imaginary part using the 2119: 192:
in the signal, or to the occurrence of harmonic frequencies (
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Norton, Michael Peter; Karczub, Denis (November 17, 2003).
2115: 2094:. A low-pass lifter is similar to a low-pass filter in the 246:
The cepstrum is used in many variants. Most important are:
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Fundamentals of Noise and Vibration Analysis for Engineers
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An important property of the cepstral domain is that the
61: 2513:(in German). Vol. 3 (3 ed.). Berlin, Germany: 1815:
Therefore: The complex cepstrum can be also written as:
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computation of the logarithm of the spectral amplitude
2189: 1932: 1824: 1653: 1568: 1537: 1513: 1416: 1293: 1228: 1191: 1075: 966: 884: 751: 612: 569: 526: 481: 424: 384: 374:, as the z-transform is a generalization of the DFT. 339: 313: 278: 85: 73: 52: 43: 2509:; Weber, Wolfgang; Heinemann, Traute, eds. (1974) . 2499: 2417:, Vol. 65, No. 10, October 1977, pp. 1428–1443. 2331:
Proceedings of the Symposium on Time Series Analysis
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estimation of speaker fundamental frequency (pitch)
2083:The autocepstrum is defined as the cepstrum of the 1887: 1879: 1784: 1776: 1710: 1702: 1611: 1603: 1371: 1341: 471:leads to simplifications (see "complex cepstrum"). 144:was derived by reversing the first four letters of 97: 70: 64: 40: 2250: 2018: 1912: 1804: 1638: 1547: 1523: 1496: 1387: 1265: 1204: 1167: 1060: 946: 857: 728: 575: 547: 495: 442: 404: 349: 319: 293: 2251:{\displaystyle x_{1}*x_{2}\mapsto x'_{1}+x'_{2}.} 1531:is complex the log-term can be also written with 2768: 2700: 2409:D. G. Childers, D. P. Skinner, R. C. Kemerait, " 2477: 2468: 2405: 2403: 2401: 2399: 2397: 2395: 2393: 2391: 2321:B. P. Bogert, M. J. R. Healy, and J. W. Tukey, 2294:A short-time cepstrum analysis was proposed by 200:). Mathematically it deals with the problem of 2429: 2427: 2425: 2423: 2363: 2361: 2359: 2317: 2315: 2313: 2311: 2357: 2355: 2353: 2351: 2349: 2347: 2345: 2343: 2341: 2339: 2388: 1999: 1986: 1483: 1468: 1367: 1352: 821: 806: 692: 677: 2623: 2486: 2420: 2308: 1219:is directly related to the power cepstrum: 175:Steps in forming cepstrum from time history 2754:Speech analysis: Cepstral analysis vs. LPC 2444: 2442: 2336: 2606: 2604: 2129:The cepstrum is a representation used in 599:The "cepstrum" was originally defined as 2048:) is related to the complex cepstrum as 362:: The abbreviation can stand i.e. for a 170: 2439: 2769: 2636: 2601: 1266:{\displaystyle C_{p}=4\cdot C_{r}^{2}} 1178:which provides a relationship to the 211: 148:. Operations on cepstra are labelled 303:Signal, which is a function of time 133:has applications in the analysis of 2569:. Support.ircam.fr. January 1, 1990 2411:The Cepstrum: A Guide to Processing 2056: 2033:is the base of the used logarithm. 1398: 405:{\displaystyle {\mathcal {F}}^{-1}} 204:of signals in the frequency space. 13: 2649: 2567:"Introduction - Discrete Cepstrum" 2065:of a cepstral graph is called the 1981: 1951: 1841: 1672: 1623: 1619: 1580: 1540: 1516: 1463: 1433: 1347: 1310: 1136: 1104: 1024: 989: 934: 898: 801: 773: 672: 635: 548:{\displaystyle \left|x\right|^{2}} 388: 342: 14: 2793: 2133:, to convert signals combined by 2101: 742:Sometimes it is also defined as: 594: 414:Inverse of the fourier transform 113:) is the result of computing the 2761:A tutorial on Cepstrum and LPCCs 2323:The Quefrency Alanysis [ 36: 2703:IEEE Signal Processing Magazine 2613: 2592: 2581: 2559: 2276:speech analysis and recognition 2261: 603:by the following relationship: 2454: 2374:. Cambridge University Press. 2213: 1942: 1936: 1893: 1873: 1790: 1770: 1751: 1735: 1716: 1696: 1677: 1667: 1633: 1597: 1585: 1575: 1548:{\displaystyle {\mathcal {F}}} 1524:{\displaystyle {\mathcal {F}}} 1486: 1480: 1474: 1458: 1377: 1335: 1142: 1130: 1030: 1018: 940: 928: 905: 892: 818: 812: 689: 683: 496:{\displaystyle \left|x\right|} 437: 431: 350:{\displaystyle {\mathcal {F}}} 288: 282: 1: 2301: 2131:homomorphic signal processing 364:continuous Fourier transform 7: 2141:. The result is called the 16:Concept in Fourier analysis 10: 2798: 368:discrete Fourier transform 18: 2777:Frequency-domain analysis 459:. The choice of the base 179: 115:inverse Fourier transform 2723:10.1109/msp.2004.1328092 2161:, which convolve in the 576:{\displaystyle \varphi } 241: 2678:10.1109/proc.1977.10747 2658:Proceedings of the IEEE 2415:Proceedings of the IEEE 443:{\displaystyle \log(x)} 2747:Speech Signal Analysis 2252: 2143:mel-frequency cepstrum 2020: 1914: 1806: 1640: 1549: 1525: 1498: 1389: 1267: 1206: 1169: 1062: 948: 870:spectrum of a spectrum 859: 730: 577: 549: 497: 444: 406: 351: 321: 295: 176: 2253: 2021: 1915: 1807: 1641: 1550: 1526: 1499: 1390: 1268: 1207: 1205:{\displaystyle C_{p}} 1170: 1063: 949: 860: 731: 578: 550: 498: 445: 407: 352: 322: 296: 174: 2756:", www.advsolned.com 2631:Manfred R. Schroeder 2629:A. Michael Noll and 2517:. pp. 272–274. 2187: 2165:and multiply in the 2063:independent variable 1930: 1822: 1651: 1566: 1535: 1511: 1414: 1291: 1226: 1189: 1073: 964: 882: 749: 610: 567: 524: 508:, or magnitude of a 479: 422: 382: 337: 311: 294:{\displaystyle f(t)} 276: 220:transformation of a 2715:2004ISPM...21...95O 2670:1977IEEEP..65.1428C 2244: 2228: 1262: 514:Pythagorean theorem 261: 2507:Steinbuch, Karl W. 2248: 2232: 2216: 2016: 1910: 1802: 1636: 1545: 1521: 1494: 1385: 1263: 1248: 1202: 1165: 1058: 944: 855: 726: 573: 545: 493: 440: 402: 347: 317: 291: 260: 212:General definition 177: 154:quefrency alanysis 150:quefrency analysis 21:Cepstral (company) 2782:Signal processing 2157:filtering of the 1282:complex logarithm 1056: 592: 591: 585:Phase angle of a 360:Fourier transform 320:{\displaystyle C} 162:cepstral analysis 121:of the estimated 2789: 2742: 2697: 2643: 2640: 2634: 2627: 2621: 2617: 2611: 2608: 2599: 2596: 2590: 2585: 2579: 2578: 2576: 2574: 2563: 2557: 2556: 2550: 2546: 2544: 2536: 2503: 2497: 2490: 2484: 2481: 2475: 2472: 2466: 2465: 2458: 2452: 2446: 2437: 2431: 2418: 2407: 2386: 2385: 2365: 2334: 2319: 2257: 2255: 2254: 2249: 2240: 2224: 2212: 2211: 2199: 2198: 2167:frequency domain 2096:frequency domain 2057:Related concepts 2025: 2023: 2022: 2017: 2012: 2008: 2007: 2006: 2002: 1998: 1997: 1985: 1984: 1964: 1963: 1955: 1954: 1919: 1917: 1916: 1911: 1909: 1905: 1892: 1891: 1890: 1882: 1869: 1868: 1854: 1853: 1845: 1844: 1834: 1833: 1811: 1809: 1808: 1803: 1789: 1788: 1787: 1779: 1766: 1765: 1750: 1749: 1731: 1730: 1715: 1714: 1713: 1705: 1692: 1691: 1676: 1675: 1663: 1662: 1645: 1643: 1642: 1637: 1632: 1631: 1630: 1629: 1614: 1606: 1584: 1583: 1554: 1552: 1551: 1546: 1544: 1543: 1530: 1528: 1527: 1522: 1520: 1519: 1503: 1501: 1500: 1495: 1493: 1489: 1467: 1466: 1446: 1445: 1437: 1436: 1426: 1425: 1405:complex cepstrum 1399:Complex cepstrum 1394: 1392: 1391: 1386: 1384: 1380: 1376: 1375: 1374: 1351: 1350: 1344: 1323: 1322: 1314: 1313: 1303: 1302: 1272: 1270: 1269: 1264: 1261: 1256: 1238: 1237: 1211: 1209: 1208: 1203: 1201: 1200: 1174: 1172: 1171: 1166: 1161: 1160: 1155: 1151: 1150: 1146: 1145: 1140: 1139: 1133: 1117: 1116: 1108: 1107: 1085: 1084: 1067: 1065: 1064: 1059: 1057: 1054: 1049: 1048: 1043: 1039: 1038: 1034: 1033: 1028: 1027: 1021: 1002: 1001: 993: 992: 976: 975: 953: 951: 950: 945: 943: 938: 937: 931: 914: 913: 908: 902: 901: 895: 864: 862: 861: 856: 854: 853: 848: 844: 843: 839: 838: 834: 833: 828: 824: 805: 804: 777: 776: 761: 760: 735: 733: 732: 727: 725: 724: 719: 715: 714: 710: 709: 705: 704: 699: 695: 676: 675: 648: 647: 639: 638: 622: 621: 582: 580: 579: 574: 554: 552: 551: 546: 544: 543: 538: 502: 500: 499: 494: 492: 449: 447: 446: 441: 411: 409: 408: 403: 401: 400: 392: 391: 370:(DFT) or even a 356: 354: 353: 348: 346: 345: 326: 324: 323: 318: 300: 298: 297: 292: 262: 259: 230:frequency domain 104: 103: 100: 99: 96: 93: 90: 87: 82: 81: 78: 75: 72: 67: 66: 63: 60: 57: 54: 51: 48: 45: 42: 28:Fourier analysis 2797: 2796: 2792: 2791: 2790: 2788: 2787: 2786: 2767: 2766: 2652: 2650:Further reading 2647: 2646: 2641: 2637: 2628: 2624: 2618: 2614: 2609: 2602: 2597: 2593: 2588: 2586: 2582: 2572: 2570: 2565: 2564: 2560: 2548: 2547: 2538: 2537: 2525: 2515:Springer Verlag 2504: 2500: 2492:R.B. Randall:, 2491: 2487: 2482: 2478: 2473: 2469: 2460: 2459: 2455: 2447: 2440: 2432: 2421: 2408: 2389: 2382: 2366: 2337: 2320: 2309: 2304: 2264: 2236: 2220: 2207: 2203: 2194: 2190: 2188: 2185: 2184: 2147:pitch detection 2110:resulting from 2104: 2085:autocorrelation 2059: 1993: 1989: 1980: 1979: 1978: 1974: 1973: 1969: 1965: 1956: 1950: 1949: 1948: 1931: 1928: 1927: 1886: 1878: 1877: 1876: 1864: 1860: 1859: 1855: 1846: 1840: 1839: 1838: 1829: 1825: 1823: 1820: 1819: 1783: 1775: 1774: 1773: 1761: 1757: 1742: 1738: 1726: 1722: 1709: 1701: 1700: 1699: 1687: 1683: 1671: 1670: 1658: 1654: 1652: 1649: 1648: 1622: 1618: 1610: 1602: 1601: 1600: 1579: 1578: 1567: 1564: 1563: 1539: 1538: 1536: 1533: 1532: 1515: 1514: 1512: 1509: 1508: 1462: 1461: 1451: 1447: 1438: 1432: 1431: 1430: 1421: 1417: 1415: 1412: 1411: 1401: 1370: 1346: 1345: 1340: 1339: 1338: 1328: 1324: 1315: 1309: 1308: 1307: 1298: 1294: 1292: 1289: 1288: 1257: 1252: 1233: 1229: 1227: 1224: 1223: 1196: 1192: 1190: 1187: 1186: 1156: 1141: 1135: 1134: 1129: 1122: 1118: 1109: 1103: 1102: 1101: 1100: 1096: 1095: 1080: 1076: 1074: 1071: 1070: 1053: 1044: 1029: 1023: 1022: 1017: 1007: 1003: 994: 988: 987: 986: 985: 981: 980: 971: 967: 965: 962: 961: 957:and therefore: 939: 933: 932: 927: 909: 904: 903: 897: 896: 891: 883: 880: 879: 849: 829: 800: 799: 798: 794: 793: 789: 782: 778: 772: 771: 770: 766: 765: 756: 752: 750: 747: 746: 720: 700: 671: 670: 669: 665: 664: 660: 653: 649: 640: 634: 633: 632: 631: 627: 626: 617: 613: 611: 608: 607: 597: 568: 565: 564: 558:Absolute square 539: 528: 527: 525: 522: 521: 482: 480: 477: 476: 423: 420: 419: 393: 387: 386: 385: 383: 380: 379: 341: 340: 338: 335: 334: 312: 309: 308: 277: 274: 273: 244: 214: 182: 123:signal spectrum 84: 69: 39: 35: 24: 17: 12: 11: 5: 2795: 2785: 2784: 2779: 2765: 2764: 2757: 2750: 2743: 2698: 2651: 2648: 2645: 2644: 2635: 2622: 2612: 2600: 2591: 2580: 2558: 2523: 2498: 2485: 2476: 2467: 2453: 2438: 2419: 2387: 2380: 2335: 2306: 2305: 2303: 2300: 2284: 2283: 2280: 2277: 2274: 2271: 2263: 2260: 2259: 2258: 2247: 2243: 2239: 2235: 2231: 2227: 2223: 2219: 2215: 2210: 2206: 2202: 2197: 2193: 2103: 2102:Interpretation 2100: 2058: 2055: 2054: 2053: 2046:phase spectrum 2042:phase cepstrum 2027: 2026: 2015: 2011: 2005: 2001: 1996: 1992: 1988: 1983: 1977: 1972: 1968: 1962: 1959: 1953: 1947: 1944: 1941: 1938: 1935: 1921: 1920: 1908: 1904: 1901: 1898: 1895: 1889: 1885: 1881: 1875: 1872: 1867: 1863: 1858: 1852: 1849: 1843: 1837: 1832: 1828: 1813: 1812: 1801: 1798: 1795: 1792: 1786: 1782: 1778: 1772: 1769: 1764: 1760: 1756: 1753: 1748: 1745: 1741: 1737: 1734: 1729: 1725: 1721: 1718: 1712: 1708: 1704: 1698: 1695: 1690: 1686: 1682: 1679: 1674: 1669: 1666: 1661: 1657: 1646: 1635: 1628: 1625: 1621: 1617: 1613: 1609: 1605: 1599: 1596: 1593: 1590: 1587: 1582: 1577: 1574: 1571: 1542: 1518: 1505: 1504: 1492: 1488: 1485: 1482: 1479: 1476: 1473: 1470: 1465: 1460: 1457: 1454: 1450: 1444: 1441: 1435: 1429: 1424: 1420: 1400: 1397: 1396: 1395: 1383: 1379: 1373: 1369: 1366: 1363: 1360: 1357: 1354: 1349: 1343: 1337: 1334: 1331: 1327: 1321: 1318: 1312: 1306: 1301: 1297: 1278:imaginary part 1274: 1273: 1260: 1255: 1251: 1247: 1244: 1241: 1236: 1232: 1199: 1195: 1176: 1175: 1164: 1159: 1154: 1149: 1144: 1138: 1132: 1128: 1125: 1121: 1115: 1112: 1106: 1099: 1094: 1091: 1088: 1083: 1079: 1068: 1052: 1047: 1042: 1037: 1032: 1026: 1020: 1016: 1013: 1010: 1006: 1000: 997: 991: 984: 979: 974: 970: 955: 954: 942: 936: 930: 926: 923: 920: 917: 912: 907: 900: 894: 890: 887: 866: 865: 852: 847: 842: 837: 832: 827: 823: 820: 817: 814: 811: 808: 803: 797: 792: 788: 785: 781: 775: 769: 764: 759: 755: 737: 736: 723: 718: 713: 708: 703: 698: 694: 691: 688: 685: 682: 679: 674: 668: 663: 659: 656: 652: 646: 643: 637: 630: 625: 620: 616: 601:power cepstrum 596: 595:Power cepstrum 593: 590: 589: 583: 572: 561: 560: 555: 542: 537: 534: 531: 518: 517: 506:Absolute value 503: 491: 488: 485: 473: 472: 450: 439: 436: 433: 430: 427: 416: 415: 412: 399: 396: 390: 376: 375: 357: 344: 331: 330: 327: 316: 305: 304: 301: 290: 287: 284: 281: 270: 269: 266: 255: 254: 251: 243: 240: 239: 238: 235: 232: 213: 210: 181: 178: 131:power cepstrum 15: 9: 6: 4: 3: 2: 2794: 2783: 2780: 2778: 2775: 2774: 2772: 2762: 2758: 2755: 2751: 2748: 2744: 2740: 2736: 2732: 2728: 2724: 2720: 2716: 2712: 2708: 2704: 2699: 2695: 2691: 2687: 2683: 2679: 2675: 2671: 2667: 2663: 2659: 2654: 2653: 2639: 2632: 2626: 2616: 2607: 2605: 2595: 2584: 2573:September 16, 2568: 2562: 2554: 2542: 2534: 2530: 2526: 2524:3-540-06242-4 2520: 2516: 2512: 2508: 2502: 2495: 2489: 2480: 2471: 2463: 2457: 2450: 2445: 2443: 2435: 2430: 2428: 2426: 2424: 2416: 2412: 2406: 2404: 2402: 2400: 2398: 2396: 2394: 2392: 2383: 2381:0-521-49913-5 2377: 2373: 2372: 2364: 2362: 2360: 2358: 2356: 2354: 2352: 2350: 2348: 2346: 2344: 2342: 2340: 2332: 2328: 2324: 2318: 2316: 2314: 2312: 2307: 2299: 2297: 2292: 2289: 2281: 2278: 2275: 2272: 2269: 2268: 2267: 2245: 2241: 2237: 2233: 2229: 2225: 2221: 2217: 2208: 2204: 2200: 2195: 2191: 2183: 2182: 2181: 2179: 2174: 2170: 2168: 2164: 2160: 2156: 2152: 2148: 2144: 2140: 2136: 2132: 2127: 2125: 2121: 2117: 2113: 2109: 2099: 2097: 2093: 2088: 2086: 2081: 2079: 2074: 2072: 2068: 2064: 2051: 2050: 2049: 2047: 2043: 2038: 2034: 2032: 2013: 2009: 2003: 1994: 1990: 1975: 1970: 1966: 1960: 1957: 1945: 1939: 1933: 1926: 1925: 1924: 1906: 1902: 1899: 1896: 1870: 1865: 1861: 1856: 1850: 1847: 1835: 1830: 1826: 1818: 1817: 1816: 1799: 1796: 1793: 1767: 1762: 1758: 1754: 1746: 1743: 1739: 1732: 1727: 1723: 1719: 1693: 1688: 1684: 1680: 1664: 1659: 1655: 1647: 1626: 1615: 1594: 1591: 1588: 1572: 1569: 1562: 1561: 1560: 1558: 1490: 1477: 1471: 1455: 1452: 1448: 1442: 1439: 1427: 1422: 1418: 1410: 1409: 1408: 1406: 1381: 1332: 1329: 1325: 1319: 1316: 1304: 1299: 1295: 1287: 1286: 1285: 1283: 1279: 1258: 1253: 1249: 1245: 1242: 1239: 1234: 1230: 1222: 1221: 1220: 1218: 1217:real cepstrum 1213: 1197: 1193: 1183: 1182:(see below). 1181: 1180:real cepstrum 1162: 1157: 1152: 1147: 1126: 1123: 1119: 1113: 1110: 1097: 1092: 1089: 1086: 1081: 1077: 1069: 1050: 1045: 1040: 1035: 1014: 1011: 1008: 1004: 998: 995: 982: 977: 972: 968: 960: 959: 958: 924: 921: 918: 915: 910: 888: 885: 878: 877: 876: 873: 871: 850: 845: 840: 835: 830: 825: 815: 809: 795: 790: 786: 783: 779: 767: 762: 757: 753: 745: 744: 743: 740: 721: 716: 711: 706: 701: 696: 686: 680: 666: 661: 657: 654: 650: 644: 641: 628: 623: 618: 614: 606: 605: 604: 602: 588: 587:complex value 584: 570: 563: 562: 559: 556: 540: 535: 532: 529: 520: 519: 515: 511: 510:complex value 507: 504: 489: 486: 483: 475: 474: 470: 466: 462: 458: 454: 451: 434: 428: 425: 418: 417: 413: 397: 394: 378: 377: 373: 369: 365: 361: 358: 333: 332: 328: 314: 307: 306: 302: 285: 279: 272: 271: 267: 265:Abbreviation 264: 263: 258: 252: 249: 248: 247: 236: 233: 231: 227: 223: 219: 218: 217: 209: 205: 203: 202:deconvolution 199: 195: 191: 187: 173: 169: 167: 163: 159: 155: 151: 147: 143: 138: 136: 132: 129:spectra. The 128: 124: 120: 117:(IFT) of the 116: 112: 108: 102: 33: 29: 22: 2706: 2702: 2661: 2657: 2638: 2625: 2615: 2594: 2583: 2571:. Retrieved 2561: 2510: 2501: 2488: 2479: 2470: 2456: 2414: 2370: 2330: 2326: 2322: 2293: 2285: 2265: 2262:Applications 2175: 2171: 2128: 2105: 2091: 2089: 2082: 2077: 2075: 2066: 2060: 2041: 2039: 2035: 2030: 2028: 1922: 1814: 1556: 1506: 1404: 1402: 1275: 1216: 1214: 1184: 1179: 1177: 956: 874: 869: 867: 741: 738: 600: 598: 468: 464: 460: 456: 268:Explanation 256: 245: 215: 206: 183: 165: 161: 157: 153: 149: 145: 141: 139: 135:human speech 130: 110: 109:, adjective 106: 31: 25: 2549:|work= 2178:convolution 2163:time domain 2159:vocal tract 2151:vocal cords 2135:convolution 2124:vocal tract 2112:earthquakes 2071:time domain 372:z-transform 226:time domain 190:reflections 186:J. W. Tukey 2771:Categories 2302:References 2731:1053-5888 2686:0018-9219 2551:ignored ( 2541:cite book 2296:Schroeder 2214:↦ 2201:∗ 2139:mel scale 2067:quefrency 1958:− 1903:φ 1871:⁡ 1848:− 1800:φ 1768:⁡ 1747:φ 1733:⁡ 1694:⁡ 1665:⁡ 1627:φ 1616:⋅ 1595:⁡ 1573:⁡ 1456:⁡ 1440:− 1333:⁡ 1317:− 1246:⋅ 1127:⁡ 1111:− 1093:⋅ 1015:⁡ 996:− 925:⁡ 889:⁡ 787:⁡ 658:⁡ 642:− 571:φ 453:Logarithm 429:⁡ 395:− 329:Cepstrum 224:from the 198:overtones 158:liftering 140:The term 127:frequency 119:logarithm 105:; plural 2533:73-80607 2242:′ 2226:′ 2153:and the 2078:kepstrum 1055: or 194:partials 166:kepstrum 146:spectrum 142:cepstrum 111:cepstral 32:cepstrum 2739:1162306 2711:Bibcode 2694:6108941 2666:Bibcode 2436:. (PDF) 2155:formant 2044:(after 1280:of the 228:to the 107:cepstra 2737:  2729:  2692:  2684:  2531:  2521:  2378:  2108:echoes 2092:lifter 2029:where 222:signal 180:Origin 30:, the 2735:S2CID 2690:S2CID 2620:2017. 2120:radar 242:Types 160:, or 2727:ISSN 2682:ISSN 2575:2022 2553:help 2529:LCCN 2519:ISBN 2376:ISBN 2288:sEMG 2116:bomb 2114:and 2076:The 2061:The 2040:The 1403:The 1215:The 366:, a 152:(or 2719:doi 2674:doi 2413:", 2325:sic 1862:log 1759:log 1724:log 1685:log 1656:log 1592:log 1570:log 1507:As 1453:log 1330:log 1124:log 1012:log 922:log 886:log 784:log 655:log 455:of 426:log 156:), 83:-,- 26:In 2773:: 2733:. 2725:. 2717:. 2707:21 2705:. 2688:. 2680:. 2672:. 2662:65 2660:. 2603:^ 2545:: 2543:}} 2539:{{ 2527:. 2441:^ 2422:^ 2390:^ 2338:^ 2329:, 2310:^ 1559:: 516:. 196:, 168:. 137:. 2763:" 2759:" 2752:" 2749:" 2745:" 2741:. 2721:: 2713:: 2696:. 2676:: 2668:: 2577:. 2555:) 2535:. 2464:. 2451:. 2384:. 2246:. 2238:2 2234:x 2230:+ 2222:1 2218:x 2209:2 2205:x 2196:1 2192:x 2031:b 2014:, 2010:} 2004:) 2000:} 1995:c 1991:C 1987:{ 1982:F 1976:( 1971:b 1967:{ 1961:1 1952:F 1946:= 1943:) 1940:t 1937:( 1934:f 1907:} 1900:i 1897:+ 1894:) 1888:| 1884:F 1880:| 1874:( 1866:e 1857:{ 1851:1 1842:F 1836:= 1831:c 1827:C 1797:i 1794:+ 1791:) 1785:| 1781:F 1777:| 1771:( 1763:e 1755:= 1752:) 1744:i 1740:e 1736:( 1728:e 1720:+ 1717:) 1711:| 1707:F 1703:| 1697:( 1689:e 1681:= 1678:) 1673:F 1668:( 1660:e 1634:) 1624:i 1620:e 1612:| 1608:F 1604:| 1598:( 1589:= 1586:) 1581:F 1576:( 1557:e 1541:F 1517:F 1491:} 1487:) 1484:} 1481:) 1478:t 1475:( 1472:f 1469:{ 1464:F 1459:( 1449:{ 1443:1 1434:F 1428:= 1423:c 1419:C 1382:} 1378:) 1372:| 1368:} 1365:) 1362:t 1359:( 1356:f 1353:{ 1348:F 1342:| 1336:( 1326:{ 1320:1 1311:F 1305:= 1300:r 1296:C 1259:2 1254:r 1250:C 1243:4 1240:= 1235:p 1231:C 1198:p 1194:C 1163:, 1158:2 1153:| 1148:} 1143:| 1137:F 1131:| 1120:{ 1114:1 1105:F 1098:| 1090:4 1087:= 1082:p 1078:C 1051:, 1046:2 1041:| 1036:} 1031:| 1025:F 1019:| 1009:2 1005:{ 999:1 990:F 983:| 978:= 973:p 969:C 941:| 935:F 929:| 919:2 916:= 911:2 906:| 899:F 893:| 851:2 846:| 841:} 836:) 831:2 826:| 822:} 819:) 816:t 813:( 810:f 807:{ 802:F 796:| 791:( 780:{ 774:F 768:| 763:= 758:p 754:C 722:2 717:| 712:} 707:) 702:2 697:| 693:} 690:) 687:t 684:( 681:f 678:{ 673:F 667:| 662:( 651:{ 645:1 636:F 629:| 624:= 619:p 615:C 541:2 536:| 533:x 530:| 490:| 487:x 484:| 469:e 465:e 461:b 457:x 438:) 435:x 432:( 398:1 389:F 343:F 315:C 289:) 286:t 283:( 280:f 101:/ 98:m 95:ə 92:r 89:t 86:s 80:p 77:ɛ 74:s 71:ˈ 68:, 65:m 62:ʌ 59:r 56:t 53:s 50:p 47:ɛ 44:k 41:ˈ 38:/ 34:( 23:.

Index

Cepstral (company)
Fourier analysis
/ˈkɛpstrʌm,ˈsɛp-,-strəm/
inverse Fourier transform
logarithm
signal spectrum
frequency
human speech

J. W. Tukey
reflections
partials
overtones
deconvolution
signal
time domain
frequency domain
Fourier transform
continuous Fourier transform
discrete Fourier transform
z-transform
Logarithm
Absolute value
complex value
Pythagorean theorem
Absolute square
complex value
imaginary part
complex logarithm
phase spectrum

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