Role of temporal amplitude modulation in Indian Political Scenario: Narendra Modi vs. Rahul Gandhi

Speech signal intrinsically have amplitude modulations in the range of 1–9 Hz. The study investigated the role of amplitude modulation, temporal and spectral features in Indian political arena by comparing speech produced by Narendra Modi and Rahul Gandhi. For both the speakers, study of modulation spectra after matching the overall intensities showed greater power in frequency range 1–15 Hz in political rallies as compared to interviews and parliamentary debates. For Interviews, greater power is seen in modulation spectra of Modi's speech sample as compared to that of Rahul Gandhi. Significant peaks were seen around 6Hz, 9Hz, 12Hz, 15Hz and 22 Hz. Modulation spectra of Rahul Gandhi's speech was found to be smooth over the entire range. Modulation spectra of both Modi's and Rahul's speech sample was found to be flat for parliamentary debates. However, more energy and significant peaks were seen around 6Hz, 13Hz and 16 Hz in modulation spectra for Rahul Gandhi's speech sample in political rallies against flat spectra for Modi. These peaks indicate use of more structured syllables in speech by the speakers to have more perceived intelligibility. Analysis on pauses, rate of speaking, pitch, use of fillers and formants for vowel pronunciation were also made.