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Topic: Spectral envelope


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In the News (Fri 24 Oct 14)

  
  Legal Envelope   (Site not responding. Last check: 2007-10-21)
Any handmade envelope is effectively a lettersheet because prior to the folding stage it offers the opportunity for writing a message on that area of the sheet which after folding becomes the inside of the face of the envelope.
Some envelopes are designed to be reused as the return envelope, saving the expense of including a return envelope in the contents of the original envelope.
But although the paper from which these first machine-made envelopes were made was cut to the shape of a rhombus or diamond and creased ready for folding to form a rectangular enclosure, it did not have the edges of the overlapping flaps treated with a paste or adhesive.
www.wwwtln.com /finance/114/legal-envelope.html   (1470 words)

  
 Stephen McAdams, Xavier Rodet: The role of FM-induced AM in dynamic spectral profile analysis (in Basic Issues in ...   (Site not responding. Last check: 2007-10-21)
This was necessary to avoid discrimination judgments based on counting the number of peaks in the amplitude envelope for the modulated pure tone condition, since with sine phase vibrato the amplitude would always increase at the beginning for one spectral envelope, and decrease for the other.
The spectral envelopes consisted of 5 formants, 4 of which were identical in the two cases.
These data suggest that even very similar spectral envelopes can be successfully identified in the presence of vibrato (and with a severely restricted set of choices), when the fundamental frequency is fairly high and the spectral envelope is not well defined by the relative amplitudes of the frequency components in the absence of vibrato.
mediatheque.ircam.fr /articles/textes/McAdams88a   (2749 words)

  
 Acoustical Society of America - Large grand and small upright pianos
They found that the spectral partials in piano tones are progressively stretched and hypothesized that the lower inharmonicity of longer strings in the bass range explains why musicians prefer grand piano tone quality over that of uprights.
The number of partials and the steps between ascending values of spectral width were chosen to obtain the same difference in spectral width produced in two ways: by changing inharmonicity without changing number of partials, and by changing number of partials without changing inharmonicity.
In the second experiment, we synthesized an A0 tone, 1 second long, whose spectrum was the combination of the spectral envelope of the real tone of the small upright piano 114-cm high with the inharmonicity of a concert grand piano tone.
www.zainea.com /lasmupiano.htm   (1188 words)

  
 Sound hybridization based on a deterministic plus stochastic decomposition mode
The spectral shape of sound2 is obtained by performing a line-segment approximation of the magnitude spectrum with a number of breakpoints given by the current value of n-spectral-coefficients.
Spectral Modeling Synthesis (SMS) is a spectrum modeling technique that models the time-varying spectra of a sound as (1) a collection of sinusoids controlled through time by piecewise linear amplitude and frequency envelopes (the ``deterministic" part), and (2) a time-varying filtered noise component (the ``stochastic" part).
The magnitude spectrum is the envelope itself, and the phase spectrum is generated by a random number generator.
www.iua.upf.es /~xserra/articles/icmc-94   (2185 words)

  
 Taxonomy of spectra
The spectral envelope describes the shape of the spectrum.
In general, sounds don't have a single, well-defined spectral envelope; there may be many ways to draw a smooth-looking curve through a spectrum.
In this model the timbre (and the loudness) are mostly encoded in the spectral envelope.
www-crca.ucsd.edu /~msp/techniques/v0.02/book-html/node71.html   (696 words)

  
 Yoshinori Shiga publications
Experimental results show that the spectral variation is evidently influenced by the fundamental frequency or the power of speech, and that the tendency of the variation may be related closely to speaker identity.
The envelope formed by these harmonics is represented by a cepstrum, which is computed by fitting the peaks of all the harmonics based on the weighted least square method in the frequency domain.
This paper introduces a novel articulatory-acoustic mapping in which detailed spectral envelopes are estimated based on the cepstrum, inclusive of the high-quefrency elements which are discarded in conventional speech synthesis to eliminate the pitch component of speech.
www.cstr.ed.ac.uk /publications/users/s0197813_abstracts.html   (1017 words)

  
 3.4.3 Harmonic component discrete cepstrum
Using the residual spectrum to derive a spectral envelope is sometimes problematic due to the presence of sinusoidal modeling artifacts in the noise component.
For this reason, we may derive a spectral envelope from the harmonic component instead, to avoid deriving a spectral envelope from potentially ill-conditioned signals.
An example showing the computed discrete cepstrum envelope on top of the partial peaks is presented in figure 3.11.
www.music.mcgill.ca /~thibault/Thesis/node44.html   (292 words)

  
 Introduction   (Site not responding. Last check: 2007-10-21)
The spectral envelope is used to determine the amplitude of the individual partials, as a function of their frequencies, and is thought of as controlling the sound's (possibly time-varying) timbre.
A simple example of this is synthesizing a plucked string as a sound with harmonically spaced partials in which the spectral envelope starts out rich but then dies away exponentially with higher frequencies decaying faster than lower ones, so that the timbre mellows over time.
A more complicated example is the spoken or sung voice, in which vowels appear as spectral envelopes, dipthongs and many consonants appear as time variations in the spectral envelopes, and other consonants appear as spectrally shaped noise.
www-crca.ucsd.edu /~msp/Publications/icmc01-paf/node1.html   (547 words)

  
 Tritone Paradox and Spectral-Motion AfterEffects   (Site not responding. Last check: 2007-10-21)
Illusions arise from Deutsch and Shepard tones when the spectral envelopes are held constant and the frequencies components are raised or lowered in pitch.
For any given spectral envelope, individual tones are ambiguous in terms of their pitch height because multiple octaves are presented simultaneously.
There is no change in the perceived pitch as a result of such spectral envelope shifts since the fundamental frequency, which determines the perceived pitch of complex harmonic tones, remains the same.
www.cameron.edu /~lloydd/webdoc1.html   (1517 words)

  
 This is the excitation demo   (Site not responding. Last check: 2007-10-21)
Regarding the spectral envelopes to the left, it is seen that the reconstructed wideband spectral envelope follows the original wideband spectral envelope much better than the narrowband counterpart, especially for the low frequencies.
However for high frequencies the narrowband and the reconstructed wideband spectral envelope start to resemble each other more and deviate from the wideband spectral envelope.
The estimated spectral envelope shown in green is used primarily for attaining the reconstructed wideband spectral envelope.
plaza.ufl.edu /hsathyen/index13.htm   (156 words)

  
 Institute for Telecommunication Sciences - 1999 Technical Progress Report
The next step is to spline interpolate between spectral peaks to establish the spectral envelope.
Following that, the OBW is specified in terms of the 99% power BW, and the NBW is specified in terms of the spectral envelope 20 dB down frequency.
The BW where the spectral envelope has rolled off by 20 dB is proposed as the NBW.
www.its.bldrdoc.gov /tpr/1999/its_e/mod_band/mod_band.html   (538 words)

  
 Spectral Description Format
The Envelope chunk can be part of several types of chunks to represent High Level Attributes of the spectral data associated to them.
An Envelope chunk includes: (1) an identifier of the type of chunk, (2) its size, (3) the type of envelope, (4) the format of the given envelope, and (5) the actual envelope data.
We have considered several envelope types: spectral shape of sines and residual spectra, pitch, amplitude of sines and residual spectra, tremolo frequency and amplitude, vibrato frequency and amplitude, articulation amplitude of sines and residual spectra, articulation pitch, and spectral tilt.
www.iua.upf.es /~xserra/articles/spectral-models/section3.html   (552 words)

  
 Spectral Envelope Estimation using a Penalized Likelihood Criterion (ResearchIndex)
Abstract: Finding a smooth spectral envelope that connects estimated sinusoids is a topic of major importance in audio signal processing.
In this paper, a penalized likelihood criterion is introduced for the estimation of the spectral envelope in the presence of measurement noise.
0.7: Estimation of the Spectral Envelope of Voiced..
citeseer.ist.psu.edu /401059.html   (279 words)

  
 Extending the Bandwidth of NarrowBand Speech Using Cepstral Linear Prediction
The enhanced speech outputs with high spectral envelope extension are then subject to both objective and subjective quality testing with respect to the original 16 kHz speech signal.
Table 1 compares the average log spectral distortion measure relative to the original speech file sampled at 16 kHz for speech enhanced using cepstral linear prediction, zero crossing enhanced spectral folding method proposed in [7] and the narrow band signal for 10 speech files from the TIMIT database.
The results however clearly show low spectral distortion when using the cepstral linear prediction method as compared to both the zero cross enhanced spectral folding method proposed in [7] and the narrow band signal when compared relative to the original wideband speech signal.
www.embeddedstar.com /articles/2004/1/article20040119-6.html   (618 words)

  
 ch2-1   (Site not responding. Last check: 2007-10-21)
The spectral analysis part of feature extraction is primarily based on the discrete Fourier transform (DFT).
In voice, the spectral envelope displays mountain-like contours or valleys known as formants.
This is also evident in violins, but the number of valleys is greater and the formant locations change very little with time unlike the voice, which varies substantially for each vowel.
www.music.princeton.edu /~park/thesis/dartmouth/html/ch2-1.html   (1714 words)

  
 Eurospeech 2003 Abstract: En-Najjary et al.   (Site not responding. Last check: 2007-10-21)
The proposed method uses a Gaussian Mixture Model (GMM) to characterize the joint distribution of the spectral envelope parameters and pitch-normalized values.
During the learning stage, the model parameters are estimated by means of the EM algorithm.
Then, a regression is made which enables the determination of a pitch prediction function from spectral envelope coefficients.
www.isca-speech.org /archive/eurospeech_2003/e03_1753.html   (149 words)

  
 Accurate Spectral Envelope Estimation For Articulation-To-Speech Synthesis (ResearchIndex)
Abstract: This paper introduces a novel articulatory-acoustic mapping in which detailed spectral envelopes are estimated based on the cepstrum, inclusive of the high-quefrency elements which are discarded in conventional speech synthesis to eliminate the pitch component of speech.
0.5: Estimation of the Spectral Envelope of Voiced..
2 Estimating the spectral envelope of voiced speech using mult..
citeseer.ist.psu.edu /679897.html   (372 words)

  
 Timbre
Helmholtz, [8], was the first person to describe musical timbre as a property of the spectral components of the sound.
The spectral envelope of a sound, the profile of the Fourier series, is still considered to be an important attribute of timbre.\
The third axis was related to the degree of spectral fluctuation in the sound, which indicates a strong dependence on the articulatory nature of the instrument.
xenia.media.mit.edu /~mkc/mitpress/node2.html   (633 words)

  
 ISCSLP 2002 Abstract: Zhu et al.   (Site not responding. Last check: 2007-10-21)
Relative to the speech production and perception models, spectral envelopes play an important role in speech analysis, synthesis, and coding.
Recently, spectral envelope estimation technique has made a rapid progress.
The work is implemented in a low bit-rate coder based on the sinusoidal model by using the different techniques to captures the spectral amplitudes.
www.isca-speech.org /archive/iscslp2002/clp2_041.html   (161 words)

  
 [No title]
When the spectral components of the ‘modifying’ function Gm are subtracted from those of the ‘primary’ function G0, the different slopes will cause a cancelling area where the weaker modifying function intersects the stronger primary function (A).
The envelope form of the filter output built-up, however, is only dependent on the filter type and bandwidth (which remain unaltered during the analysis) and is scaled by the filter value at the current frequency.
To test the spectral analyzing methods, however, it is quite convenient to be able to define the signal parameters of the test signals independently of each other, which is not possible in the case of the cascading filter concept.
fonsg3.let.uva.nl /Proceedings/Proceedings24/tonwempe/proc24art.doc   (4325 words)

  
 6.4.2 Spectral envelope interpolation and application
Once the noise source has been synthesized, we must sculpt its uniformly distributed spectrum, to simulate the filtering action of the vocal tract.
To appropriately shape the noise spectrum, we need to derive a spectral envelope from each frame of data.
This spectral envelope may be estimated either from the noise component or from the harmonic component as seen in section 3.4.
www.music.mcgill.ca /~thibault/Thesis/node70.html   (169 words)

  
 An Analysis of Spectral Envelope Reduction via Quadratic Assignment Problems
A new spectral algorithm for reordering a sparse symmetric matrix to reduce its envelope size was described in [Barnard, Pothen, and Simon, Numer.
We describe related 1- and 2-sum problems; the former is related to the envelope size, while the latter is related to an upper bound on the work in an envelope Cholesky factorization.
This provides a stronger justification of the spectral envelope reduction algorithm than previously known.
epubs.siam.org /sam-bin/dbq/article/27470   (279 words)

  
 Calculating Pitch Frequencies - Acoustic Guitar Forum
For the lower strings it's a lot trickier because the windings cause the strings to be inharmonic and the top-plate/backplate and the cavity mess with the spectral envelope and therefor the partial amplitudes.
Since it is the spectral envelope you get to adjust with with your EQ, you need to really on your ears and any visual aids you can find, e.g.
The Q corresponds to the "peaky" shape of the bumps in the spectral envelope.
www.guitarseminars.com /ubb/Forum1/HTML/002690.html   (1477 words)

  
 The spectral envelope and its applications, David S. Stoffer, David E. Tyler, David A. Wendt   (Site not responding. Last check: 2007-10-21)
The concept of the spectral envelope was recently introduced as a statistical basis for the frequency domain analysis and scaling of qualitative-valued time series.
In the process of developing the spectral envelope methodology, many other interesting extensions became evident.
On estimation of the Walsh-Fourier spectral density of two dimensional strictly homogeneous random fields.
projecteuclid.org /Dienst/UI/1.0/Summarize/euclid.ss/1009212816   (890 words)

  
 Auditory Models
The vOICe goes well beyond the use of the spectral envelope to trace out (the edges of) object shapes, and seeks to induce a full spectral-temporal integration by the human brain to arrive at a form of mental synthetic vision.
One (and ultimately decisive) approach is to perform direct psychoacoustic experiments with human volunteers, involving all the intricacies of dealing with human variability.
The auditory spectrogram is a plot of a sequence of spectral slices extracted from the envelope of the basilar membrane motion.
www.seeingwithsound.com /aumodel.htm   (1331 words)

  
 Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations   (Site not responding. Last check: 2007-10-21)
Energy Citations Database (ECD) Document #6752286 - Dependence of astigmatism, far-field pattern, and spectral envelope width on active layer thickness of gain guided lasers with narrow stripe geometry
Availability information may be found in the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or via the "Full-text Availability" link.
Dependence of astigmatism, far-field pattern, and spectral envelope width on active layer thickness of gain guided lasers with narrow stripe geometry
www.osti.gov /energycitations/product.biblio.jsp?osti_id=6752286   (120 words)

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