*Article* **Linguistic Laws in Speech: The Case of Catalan and Spanish**

#### **Antoni Hernández-Fernández 1,2,\*,†, Iván G. Torre 3,†, Juan-María Garrido 4 and Lucas Lacasa 5,\***


Received: 31 October 2019 ; Accepted: 21 November 2019; Published: 26 November 2019

**Abstract:** In this work we consider Glissando Corpus—an oral corpus of Catalan and Spanish—and empirically analyze the presence of the four classical linguistic laws (Zipf's law, Herdan's law, Brevity law, and Menzerath–Altmann'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 agreemen<sup>t</sup> 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' 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.

**Keywords:** Zipf's law; Brevity law; Menzerath–Altmann's law; Herdan's law; lognormal distribution; size-rank law; quantitative linguistics; Glissando corpus; scaling; speech
