A Methodology for Recognition of Emotions Based on Speech Analysis, for Applications to Human-Robot Interaction. An Exploratory Study

A system for recognition of emotions based on speech analysis can have interesting applications in human-robot interaction. In this paper, we carry out an exploratory study on the possibility to use a proposed methodology to recognize basic emotions (sadness, surprise, happiness, anger, fear and disgust) based on phonetic and acoustic properties of emotive speech with the minimal use of signal processing algorithms. We set up an experimental test, consisting of choosing three types of speakers, namely: (i) five adult European speakers, (ii) five Asian (Middle East) adult speakers and (iii) five adult American speakers. The speakers had to repeat 6 sentences in English (with durations typically between 1 s and 3 s) in order to emphasize rising-falling intonation and pitch movement. Intensity, peak and range of pitch and speech rate have been evaluated. The proposed methodology consists of generating and analyzing a graph of formant, pitch and intensity, using the open-source PRAAT program. From the experimental results, it was possible to recognize the basic emotions in most of the cases