Linguistic Laws in Speech: The Case of Catalan and Spanish

In this work we consider Glissando Corpus&mdash
an oral corpus of Catalan and Spanish&mdash
and empirically analyze the presence of the four classical linguistic laws (Zipf&rsquo
s law, Herdan&rsquo
s law, Brevity law, and Menzerath&ndash
Altmann&rsquo
s law) in oral communication, and further complement this with the analysis of two recently formulated laws: lognormality law and size-rank law. By aligning the acoustic signal of speech production with the speech transcriptions, we are able to measure and compare the agreement of each of these laws when measured in both physical and symbolic units. Our results show that these six laws are recovered in both languages but considerably more emphatically so when these are examined in physical units, hence reinforcing the so-called `physical hypothesis&rsquo
according to which linguistic laws might indeed have a physical origin and the patterns recovered in written texts would, therefore, be just a byproduct of the regularities already present in the acoustic signals of oral communication.