Software for Sound Modeling, Morphing, and Manipulation

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Loris is an Open Source sound modeling and processing software package based on the Reassigned Bandwidth-Enhanced Additive Sound Model. Loris supports modified resynthesis and manipulations of the model data, such as time- and frequency-scale modification and sound morphing.

The Loris programmers' interface supports the C, C++, and Python programming languages, and SWIG interface files are provided so that the API can be easily extended to a variety of other languages. The package includes a handful of utility programs for basic sound modeling and resynthesis, and standard UNIX/Linux tools that build and install the libraries, headers, and utilties.

Loris was developed by Kelly Fitz and Lippold Haken at the CERL Sound Group, and is distributed under the GNU General Public License (GPL).

More information and a list of publications about the time-frequency analysis methods implemented in Loris, including the method of time-frequency reassignment and the reassigned bandwidth-enhanced additive model, are available at Kelly's research page.


You can download the Loris software package from our project website at SourceForge.

Get Loris at SourceForge.net. Fast, secure and Free Open Source software downloads

To download Matlab scripts implementing time-frequency reassigned spectral analysis, please visit Kelly's research page.

To receive occasional status reports, release notices, and other announcements concerning the Loris project, please subscribe to the extremely low-traffic Loris‑announce mailing list.

Documentation and Tutorials

This area was eternally under construction, please pardon our dust.


Loris API Documentation:

The Loris Python module (loris) is fully documented using pydoc. At the Unix command line, type, for example

pydoc loris.Analyzer

to see the documentation for the Analyzer class, or in the python interpreter,

>>> from pydoc import help
>>> help(loris.Analyzer)

For a list of publications discussing Loris and the reassigned bandwidth-enhanced additive model, please visit Kelly's research page.


Previous sound modeling research at the CERL Sound Group was based on the signal decomposition method of McAulay and Quatieri (see, for example, R.J.McAulay and T.F.Quatieri, "Speech Analysis/Synthesis Based on a Sinusoidal Representation," IEEE Transactions on Acoustics, Speech, and Signal Processing, ASSP-34, 1986. pp. 744-754), wherein short time Fourier analysis is used to find spectral energy peaks, and peaks in successive analysis frames are linked to form sinusoidal partials.

An enhanced McAulay-Quatieri analysis algorithm was impemented in Lemur, a widely distributed shareware Macintosh application for sound analysis, transformation, and synthesis.

Lemur is no longer under development, nor is it supported in any way.

Go to the CERL Sound Group website.
Go to Kelly Fitz's home page.

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Last update: 29 February 2012