#### Note: this recognizer runs on a web server, the audio file will be uploaded using HTTP.

### How to use the Tag Vowels recognizer from within ELAN

The Tag Vowels recognizer written at the Max Planck Institute for Psycholinguistics uses the Praat analysis of f0 (pitch) and volume of a given audio recording to spot timespans which are likely to correspond to spoken vowels. This can be interesting for measuring speech rate (counting syllables per time) or for gathering information about prosody: The raw Praat data is available as additional output. The web service version has Praat installed on the same server, but it is also possible to install the recognizer on the computer where ELAN is running. In that case, Praat has to be installed first. The Praat software is available for Linux and Windows from UvA, it is free open source software. The recognizer itself is available, also as free open source software, from the MPI for Psycholinguistics. This recognizer also demonstrates the various types of possible input, output and setting objects within the AVATecH and AUVIS frameworks.

- Input: A single audio recording in a file format supported by Praat, for example uncompressed PCM *.wav files. When installed locally, it is also possible to provide precomputed Praat output as additional input file, overriding the default processing of the recognizer.
- Settings:
  - max_f0 defines a pitch ceiling: For example if a recording is known to have no young or female speakers, this can be set to 300 Hz to keep Praat from matching pitch in a higher octave by accident.
  - epsilon selects how much the volume (in decibels) has to change to mark the edge of a peak. High epsilon only triggers on sharp volume peaks, for example.
  - Silence threshold selects the minimum amplitude (on a scale from 0 to 1) required for pitch analysis. It is often not interesting to assign pitch to relatively silent timespans.
  - Voicing threshold selects how regular a bit of sound has to be to count as voiced. Noise is very irregular, vowels are quite regular, a sine wave beep is very regular.
  - Loglevel gives a choice of three verbosity settings. Lowest is normal, verbose gives some additional information and debug gives a lot of not normally interesting additional information.
- Output: Two different sets of tiers, in two different formats (default XML or compact CSV) each are available: One set annotates average pitch and volume, the other set annotates initial, final, minimal and maximal pitch. In addition, a timeseries output option is available. This data can be visualized by ELAN as curves of pitch and volume. The recognizer produces it by gathering Praat output for each segment of 1/100th second. Unvoiced segments have undefined pitch, which ELAN may visualize as gaps in the curve or as '0 Hz' pitch.

AVATecH and AUVIS compatible recognizers have the following categories of settings, input and output elements:

- input media: ELAN automatically uses the first suitable media file of your current annotation session, but you can change that to other supported files belonging to the session. Very few recognizers expect multiple input media files or extra input files in 'timeseries' or recognizer-specific formats.
- input tiers: Some recognizers need input in the form of an annotation tier, for example to select timespans of interest. For some recognizers, the input is expected to be the output of another recognizer. This gives you a chance to edit and correct data - often simply tiers - between the two steps.
- numerical input: Recognizers can be configurable by numerical 'knobs'. ELAN can show those as slider or field. Recognizers often work well enough with defaults already.
- choice input: Recognizers can give you the option to select settings from a pre-defined list. An example can be 'verbose/normal/silent' messages or 'high/low' sensitivity. ELAN shows drop down selectors here. In special cases, a recognizer can also have 'any text' configuration items.
- output: Recognizers often produce one or more annotation tiers. ELAN will offer to add those to your annotation session as new tiers. It is also possible for recognizers to output timeseries (which ELAN can show as curves) or even audio, video or other files. Most recognizers only produce zero or more tiers (plus log messages) as output. It is often possible to selectively skip some output steps.
- log: You can open a window showing general messages from the recognizer, tagged by type (e.g. DEBUG, INFO, WARN, ERROR, RESULT or PROGRESS). Messages of higher priority also update the processing status display, so they can be seen directly without having to review the log text.
- basic or advanced recognizer settings: ELAN gives you the choice to either hide or show 'advanced' settings. Default values will be used for those settings which are hidden.

Your default ELAN configuration invokes a CLAM REST web service wrapper on catalog.clarin.eu to have your files analyzed. In other words, your media files and, if applicable, input tiers will be uploaded for processing and ELAN will process the downloaded (tier or other) results as if you had done the processing locally. For use in situations where a web service can not be used (too large files or no internet available) you can also request a copy of the recognizer for local installation on Linux or Windows, protected by USB dongle.

For this and for general support with the use of this recognizer, please contact auvis@mpi.nl or use the ELAN and AUVIS forums on the website of The Language Archive.

CLAM, ELAN and the client-side recognizer proxy are free open source software under the GNU General Public License - however, some of the recognizers can be propietary closed source software. Licenses for academic use are available on request. Use of the web services is free at the moment, but may be limited to the academic community if it becomes necessary.