Shivam Sharma

Component Characterization of Western and Indian Classical Music

Regular pitch detection algorithms are known to be immensely useful for speech source analysis. Their utility is not as reliable when processing polyphonic acoustic mixtures like Music. This is an investigative study of music components like rhythm, accompaniment and Lyrical-voicing, that is seen as a critical task towards targeted music component identification and processing. Popular music forms like Western and Hindustani Classical are considered for our study dataset. For Western cases, comparative preliminary analysis of the spectral characteristics like Harmonics and Energy is done towards characterization of Music region against that of Lyrics-music mixture. \(F_{0}\) contour analysis for these regions, using Autocorrelation and Zero frequency filtering indicates the utility of the latter in Lyrical-voicing onset identification. Short-time spectral analysis leads to the distinctive understanding about the Harmonic structure according to the music polyphony. Strength of Excitation is found to be insightful towards characterizing sounds like base sounds, prominent in percussion instruments. For study on Classical music, \(F_{0}\) contour analysis using raw signal and LP Residual elucidate the characteristic average pitch effect, which comes out to be higher for the Alaap region in case of Female artists and Lyrics composition regions for the Male artists, giving cues towards the applications like Raaga identification and summarization. The analysis of the excitation source features for various music components done in this work present some insightful observations and clues towards effective Music component processing.

Wireless audio communication over Infra-Red medium

In the modern era, a number of devices are going to dominate every sources of human in their day to day daily lives. These devices may be connected and/or controlled through Web, infra-Red (IR) and other means. Hence, exploring alternative means of communication is not only important but may also help towards mitigating the risk of security breach in communication channels. In this paper, we explore the possibility of communicating speech and music, over IR channel. Audio communication using an IR transmitter source and atmosphere as a medium is proposed. A prototype communication set-up is designed, in which an optical wireless transmitter using an IR emitting LED acts as a source and a photo-diode as a receiver. The methods Intensity Modulation (IM) and Direct Detection (DD) are used for modulating the signal in transmitter and for demodulation in the receiver, respectively. The Line of Sight (LoS) communication is established between the transmitter and the receiver. Experiments are conducted to measure the transmitter signal range and coverage space, in the terms of Elevation angle (θ) and Azimuth Angle (φ) with respect to distance (r). Measurements are taken for four different Infrared Levels (IL) of IR signal intensity. Each level here consists of a number of IR emitting LEDs, placed in concentric circles, as part of the transmitter source. Initial results are encouraging and establish the feasibility of speech communication over IR channel. Results also indicate that range and coverage area of the modulated signal increase by increasing the intensity of Infra-Red light, which is dependent upon the number of IR LEDs in the cluster.