Extant Parts of Methodology Section

There are 7 different threads:

1. Word prominence (Richard)

Looking at effect of functional loading on realisation of function words

1.1	Design and record a database (5 speakers) containing a representative set of function words in a variety of metrical contexts. Measureable objective: an elaborated parametric labelling system; a labelled database containing function words in a systematically varied range of structures.
1.2	Conduct an analysis of the material in the database using and expanding techniques already established for the current database. These include regression tree analysis, alongside other well-established linear statistical techniques. Establish patterns of systematic variability.  Measureable objective: a set of phonetic descriptions of function words, including descriptions of ranges of variability.
1.3	Modify the parser so as to (1) identify function words (2) generate appropriate linguistic structures for them. Measureable objective: a parser capable of generating phonological structures which integrate syntactic and phonological constraints.
1.4	Establish statements of phonetic interpretation which model the appropriate temporal and spectral details.  Measureable objective: a device-independent set of phonetic interpretation statements which can be implemented in eg. HLsyn and/or MBROLA.
1.5	Perceptual tests. Measureable objective: improved intelligiblity under adverse listening conditions. Greater ‘naturalness’ of synthetic speech.

2. Intonation (Jill)

Current work will be extended to systematic variation caused by differences in discourse function.  Specific objectives are:

2.1	To codify and implement the phonetic and phonological knowledge required to generate synthetic speech which reproduces the natural expressiveness and variation of spoken discourse.  This includes the phonetic consequences of shifts in focus, foregrounding/backgrounding, word predictability and parenthetical expressions. 
2.2	To integrate systematic temporal, intonational and segmental details for the structures developed into a system-independent description.
2.3	To evaluate the model in both concatenative and formant synthesis using perceptual criteria of naturalness and robustness.

3. Segmental quality (Sarah)

3.1	Procsy/HLsyn will be developed as ProSynth’s formant synthesizer. Sensimetrics has agreed to release the HLsyn source code for rewriting onto a Unix platform, rather than the current PC. HLsyn is an appealing platform for formant synthesis by rule because it allows the complex acoustic consequences of vocal tract dynamics at segment boundaries to be easily synthesized, and because its parameters can straightforwardly be used in order to translate linguistic structure into acoustic specifications. Procsy will be rewritten from its current stand-alone state, based on Python, into xxPRO-XML? for full compatibility with other ProSynth software. Some parameters are already assigned values by rule (see §2A). Values for parameters that are currently added by copy-synthesis (e.g. formant frequencies) will be calculated from target values, using principles of temporal overlaying developed in YorkTalk.

3.2	Knowledge of the spread of /r/ and /l/ resonance effects gained form the current grant-period will be included: a research question is to what extent these can be represented in the higher-level prosodic structure vs. at featural or segmental levels. Both levels of representation may be necessary, depending on the balance between prosodic and segmental constraints on the spread of resonance effects. Durational values for content words will vary with changes in focus [xxor similar term] due to changes in the prosodic structure, and with whether the phrase has main or parenthetical status in the utterance. Local segmental and stress conditions determine whether durations can simply be shortened (nonlinearly, cf. Klatt 19xx) or whether entirely different spectral properties are needed. For example, when catapult is spoken fast, the acoustic properties of syllable 1 (cat) change much less than those of syllable 2 (tap), which may become devoiced and raised to the extent that it is primarily an alveolar affricate. What happens spectrally to cat when it is spoken fast can probably be largely modelled as target undershoot; whereas entirely different targets must be specified for tap. Such differences can be efectively produced by PROCSy/HLsyn; they would require selection of a different unit form the concatenative synthesis database.

4. Articulation Rate (Jana)

?

5. Dissemination (Mark)

5.1	Interfaces with Festival and Laureate.  Involves importing and exporting linguistic structures to be compatible with the higher and lower levels of these systems.

5.2	Interfaces with text generated by SOLE project  Involves accepting XML marked up text generated by the ILEX text generation package as used in SOLE.

5.3	Incorporation of HLSyn as alternative output channel.  Involves recompiling HLSyn for Unix and PC platforms, integrated with existing ProSynth software.

5.4	Web-based demonstration system.  Involves providing web access to ProSynth software for on-line demonstrations.

5.5	Software portability.  Involves configuration of software to maximise portability across computing platforms.

6. Interfaces to other projects

7. Databases (John)

7.1	The database sentences will use a museum context. This will allow the material to be framed in an appropriate discourse context, which will facilitate both production and testing. Material for each of the datasets will be gathered from five speakers of the same variety (2 female, 3 male), but one speaker (male) will be common to all the datasets for comparison and in order to produce a speech signal that is coherent/sounds like it comes from one speaker. Recording to be done at UCL? The database material will allow systematic investigation of the phonetic interpretation of the function word system, such as the spectral and durational effects of /D/ (eg. in a vs. in the), the quality of schwa (in a pit vs. in a pot), and systematic parametric reorganisation (eg. she was /Si w@z/ and /Syz/). Attention will be focussed initially on prepositions, determiners and Pronoun+Auxiliary structures. The required contrasts will be placed in a systematically varied range of structures. This will allow for the analysis and modelling of rhythmical, temporal, spectral and intonational effects in a discourse-sensitive manner.