Presented at the 28th World Congress of the International Association of Logopedics and Phoniatrics, Athens, Greece, 22–26 August 2010

Although the mechanisms of speech production are the same for all humans, language-specific differences necessitate data collection from each linguistic community and evaluation of the appropriate sets of parameters in the specific contexts. Domains in which the need for language-specific data is obvious include:
- Rhythmic properties, depending in large part on phonotactic constraints related to consonant clusters at syllabic onset and coda, constrain the average and maximum speech rate. Languages with few clusters and open syllables are expected to have different vowel durations and syllable rates.
- Phone duration as a distinctive characteristic can greatly affect the variance of syllable lengths in constant-rate articulation
- Phonatory characteristics are used distinctively in some languages but are rarely found in others. This affects the range of “normal” voice parameters hence the criterion for diagnostic concern.
- Culture-specific variation in voice styles greatly affects pitch parameters.
- Different vowels have different intrinsic duration and pitch, and these differences depend on the linguistic community.
The aforementioned cases may lead to relatively small differences when considered informally, but in the context of clinical setting in which reliability and validity are of importance, an accumulation of errors can lead to gross reductions in diagnostic reliability and, consequently, to devaluation of a fundamentally sound examination procedure. Furthermore, normative voice data are indispensable in clinical and research settings, as prerequisites to the assessment of medical conditions related to the phonatory and articulatory systems, but also as assays of progress in treatments of ailments affecting spoken language indirectly, including neurodegenerative and acute nervous disorders. In this seminar we will present a voice and speech protocol derived from Greek voice data from a large representative sample of the Greek population and we will derive normative data of significance for diagnostic and assessment purposes, based on the current literature and advanced technological capabilities.