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The Science of Sound

A visit with Nandhu Radhakrishnan, Assistant Professor of Communication Science and Disorders

By Sean Powers
Published: - Topics: western classical singing professional speaking taan gestures communication voice exercise
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Picture a college professor standing at the front of a crowded auditorium and speaking to a group of three hundred students. The speaker, sharp-eyed and astute, has a glass of water and stands tall and mighty behind a podium. He projects a series of sounds toward the dreary-eyed students – a mouthful of verbs, adjectives and nouns, all carrying different meanings. The speaker’s information may be fascinating and well organized, but one MU researcher doesn’t ask why someone is speaking.  He’s more interested in studying how the speaker is communicating.

Nandhu Radhakrishnan, Assistant Professor of Communication Science and Disorders, explains that strengthening speech is not as simple as AHHHH to BAHHHH. “Improving voice begins by understanding what you really do,” he says. “Most of the time we talk, but we do not focus on how we really sound, and that is one of the reasons why we are surprised when we listen to our recorded voice and think, ‘Gosh, is that me?”’

Radhakrishnan asked himself that question several years ago when he first started working in speech pathology. As a child growing up in India, he dreamed of becoming an actor and filmmaker, but his parents had other plans for him: “Coming from a family of doctors – my dad, his dad, and grandparents were all doctors. They wanted me to be in the medical field. I did not get the courage to tell them that I wanted to be an actor, and did not want to be just another doctor in the family, so I looked for other professions and landed in speech pathology."

Today, Radhakrishnan focuses his research on how voice production creates an intricate balance among several systems of the human body, including the lungs, larynx, and vocal cords or, technically, vocal folds. Radhakrishnan demonstrates these systems at work by wrapping a non-invasive collar, with two electrodes attached, around his neck. Every time he speaks, his vocal chords come together and then separate. The two electrodes measure the frequency and extent of vocal fold contact. Radhakrishnan then cups what looks like a small respirator over his nose and mouth. This aerodynamic system estimates airflow and lung pressure.  Finally, a microphone is used to collect wave signals for processing by a computer program. The computer software breaks down the sound into voice, lung pressure, airflow, and vocal fold contact information. These separate readings help Radhakrishnan study the range of voice production.

The purpose of breaking voice into segmented readings is to identify weak spots, and then to develop exercises for people to speak effortlessly and not wear out their voice. As it turns out, the human voice ages just like the rest of the human body. While we all start off sounding tiny and high-pitched, everyone’s voice gradually deepens and matures. Radhakrishnan says it’s important to keep the vocal systems in shape: “As a human being gets older, there is a muscle stage called atrophy that affects muscle strength. When we look at the person’s physiological age, we might have to access the level of support for patients and keep the subject functioning to his or her physiological age.”

A major aspect of Radhakrishnan’s research, and the focus of his doctoral dissertation, involves comparing the vocal differences between Western and Indian classical singers. In Western tradition a classical singer would usually not try to hold a note steady because it wouldn't sound appealing to an audience. In India, however, sustaining a note steadily for a long period is seen as a talent linked to "fine motor control." Another major difference is that in the Western sphere a nasal intonation is not considered attractive, while in India nasal intonation is met with a positive response. Finally, Indian classical singers tend to use taan gestures, fraternal pitch fluctuations that require more voluntary control. Conversely, Western classical singers use an involuntary mechanism like vibrato, which is generally not controlled voluntarily.

Based on his observation and studies, Radhakrishnan came to the conclusion that Indian classical singers do not reach loudness levels as much as their Western counterparts, may be due to the difference in breath support used. This discovery may help singers in both cultures manage their vocal talents, and is of course not meant to show favoritism to one form of singing over the other. "I would say that, defining them for the purpose of singing, they are both right in their own ways," he suggests.
 
During the summer of 2007 Radhakrishnan traveled to India to study the expression of emotions in classical singing.  The subjects for this study consisted of a group of singers instructed to perform by using different levels of emotions like happiness and sorrow. The level of analysis was aimed at the point where the pitch and note were common in both songs. The emotions produced vastly different responses. “We found that for joy, the muscles get a little more excited or tense and the closure of the vocal chords was much greater than for the note where the singer was sad,” he says. Radhakrishnan’s next project will compare the emotional vocal responses of Indian with Western classical singers: “It will be a comparison to see if human beings are similar in expressing emotions or completely different.”   

One of Radhakrishnan’s other upcoming projects is closer to home. This study will examine vocal problems that Columbia Public School teachers experience after a long, draining week in the classroom. Radhakrishnan predicts teachers who are responsible for a group that is not well behaved, such as kindergarteners, would have more voice problems than those leading an older and more disciplined group of students. “The survey will focus on how their voice is before and after teaching by the end of the week,” he explains. “The results could be surprising.”

As a researcher Radhakrishnan studies voice production, but he also teaches a class on professional voice improvement. The course attracts students in a wide-range of fields including journalism, business, and theatre: “We work on exercises during the class, and learn some techniques where they can improve their voice in four or five months, and use that as an approach for presentations or when they are giving a talk.” Radhakrishnan says he would like to team up with the School of Journalism and Department of Communication to help aspiring broadcast anchors and performers with their voice production: “My goal is to spread the word about professional voice and get people to know that it is not difficult to improve voice.”