ingo titze, ph.D.

Published on July 3, 2016

Pleased to post an interview with Dr. Ingo R. Titze. Please credit The Voice Forum when you share our content.


He is one of the world’s leading voice scientists, as well as an accomplished tenor, singing teacher, and a regular contributor to the Journal of Singing. He is the University of Iowa Foundation’s Distinguished Professor of Speech Science and Voice. He has degrees in Electrical Engineering (B.S.E.E., M.S) and Physics (Ph.D.)

Dr. Titze’s contribution to our understanding of how the vocal folds work is immeasurable; he has published over 400 articles on voice. He is the author of “Principles of Voice Production” which is used worldwide as an introductory text and has been translated into multiple languages. His book “The Myoelastic Aerodynamic Theory of Phonation” is used by engineers and physicists. He is the co-author of “Vocology,” written for clinicians and vocal pedagogues, and he has also authored “Fascination with Human Voice” for the general public. Born in Germany, Dr. Titze is bi-lingual and bi-cultural. He is a founding member of Pan American Vocology Association and its current president. He is the inventor of Pavarobotti, the singing robot.


TVF: Would you tell us in layman’s term, what your research is about?

IRT: My research is pretty much everything about vocalization, both human and animal. I am interested in how all species produce sound. I am interested in making that knowledge applicable to singers, public speakers, ordinary speakers, people who sing in choirs, and anybody else who uses their voice on a regular basis. Our most important targets have been teachers in public schools who talk all day long and often fatigue.


TVF: What inspired you to conduct this research?

IRT: Well you know, I walk around all day carrying questions about voice in my head. I immerse myself into groups of people that are not so much academicians but people who practice and utilize voice on a daily basis. Some years ago, as we began to mingle with teachers, we found out that clinics are full of teachers who can’t make it through the week. They start out okay on Monday but fatigue a little bit more every day, and by the weekend they don’t have any voice left. I also spend a lot of time visiting the studios of singing teachers, seeing what their needs are, and what questions they have. A decade ago I teamed up with some people who study vocalization of animals - mammals, birds, and reptiles. They have many questions I can help answer. I get motivated less by being in my office or lab than by going to the people who have the questions.


TVF: In what ways can your research be applied in the clinical field?

IRT: My team and others around the world have discovered, scientifically, the merits behind various different voice therapy techniques. They can be all covered with one phrase called “semi-occluded vocal tract” methods. What we mean by that is, in order to make the vocal folds function in the most efficient way, one needs to practice with the mouth almost closed. So we do exercises like lip trills, or making a sound through a thin straw. I have a video on YouTube explaining straw phonation. It has been viewed by close to 100 thousand people now. There are other varieties of semi-occluded vocal tract exercises, such as tongue trills and hums. Some people promote water bubbling with a straw. All of these techniques have one thing in common. They create a pressure in the oral cavity that helps to set the vocal fold into their ideal position. The nearly closed tube also helps to create a feedback so that the acoustic pressures in the mouth help to drive the vocal folds, increasing the efficiency of the sound production. That to me has been a most significant discovery that reaches across speaking, singing, and every other kind of vocalization.


TVF: What if you hear air coming out of the nose during straw phonation?

IRT: The velum should never be open during straw phonation. Subjects should think they are making a /p/ sound, which will raise the velum. If sound or air escapes through the nose, then the technique is not effective because there is too much opening. If you close the mouth and just do an /m/, /n/ or [ng], then that is perhaps enough of a semi-occlusion, but if you use a straw and let the air go through the straw and also through the nose, then there is too much opening, so that’s not semi-occluded enough.


TVF: Does the length of the straw matter?

IRT: The length matters much less than the straw diameter, but a longer straw is an advantage if the diameter is large, like a drinking straw.


TVF: Why does the semi-occluded effect last as long as it does?

IRT: We still don't have the answer for that. A motor memory seems to be created quickly.


TVF: How will understanding the voice production mechanism make someone a better singer?

IRT: Well there are two kinds of people that are performers, and I have trained some myself. There are those who are very analytical and they always ask the questions “why do you want me to do this?” or “what does this do?” They don’t continue until they have their question answered. Then there is the kind of performer who says “tell me what to do and don’t make it complicated”. For those singers all the analytical instruction don’t help. They help the teacher, however, to figure out the best exercises for the given individual. I was one of those analytical singers. I took lessons with a well-known teacher in Seattle many years ago. We could never go on with a song or exercise until I had my questions answered. He became very frustrated with me because I wasn’t making enough progress with my voice. I was, however, making progress with my brain.


TVF: What advice would you give for clinicians who are having difficulties helping their patients increase their proprioception?

IRT: First I would have them listen to their own speech and ask where they feel the sound is coming from. Usually they’ll point to the throat. Then I have them do the semi-occluded vocal tract exercise. I would give them a thin straw and have them phonate through it for 3-5 minutes. Then I would have them speak a few words and ask them where they feel the sound coming from, and most of them will usually say “I don’t know… it feels like it’s coming out of my eyes, or my face.” They feel the sound higher than they ever did before. And that’s the proprioception that you are looking for because when you feel the sound in your face that means that sound has been efficiently produced and it’s traveling in waves up and down the vocal tract. To me, that’s the sort of the hook that I find useful. They have to get a feeling of light easy buzzing so they can counteract that with the feeling of strain. I recommend anywhere from 3-5 minutes. Frequency of practice is often better than a long single practice. In the summer I teach 4-5 hours in a row. I usually do a little bit of straw phonation after the first hour for 3 minutes. Then I do it again several times during the day. It’s a resetting of the voice to a more easy production.


TVF: Do you advocate pitch glides even with the coffee stirrer diameter straw?

IRT: Oh absolutely. That is the main exercise. Go as high as you can in pitch. Literally go to the limits. The beauty of semi-occluded exercises is that, because the amplitude of vibration is small, the vocal folds remain separated and there will not be much collision that wears out your voice. Pitch glides stretch the vocal ligament, which is very important to keep the voice flexible.


TVF: How has understanding of voice science shaped your own singing, as I know you are a very accomplished tenor?

IRT: I was one of those persons who suffered because my speaking voice was not well placed. As a child I grew up in Germany, in an environment around the dinner table where there was always very loud speech. I developed very tight and pressed speech habits, and I realized that pressed voice does not connect well to a singing voice, especially if you want to sing in mid-registration at high pitches. So I had to really work hard to break through that poor connection between two voices. I am still working on it. Every day I have to prevent reverting back to the habits that I adapted to as a young boy. For some people, it’s constant resetting of the voice. It may never be permanently fixed. You have to keep bringing it back to a central placement.


TVF: What is Vocology?

IRT: Vocology is study of vocalization. You can compare that to audiology, which is study of hearing. We are trying to develop a more specific title for clinical vocologists, or certified vocologists, similar to a certified audiologist. That would be someone who knows how to habilitate or rehabilitate voices. We stress habilitation more than rehabilitation because we deal with so many people who need voice beyond just conversational speech.


TVF: What do you think the next steps are in growing the field of Vocology?

IRT: I am the president of a new association called Pan American Vocology Association. What I hear from the members is that they want a clear training program. They want both didactic training and clinical training beyond what one gets in a normal speech-language pathology program, or what one gets in a normal music school. They are all recognizing that the field has grown and there is so much knowledge about voice that isn’t being taught in traditional departments.


TVF: What do you think were the most important contributions in the past years in the field of Voice?

IRT: The first thing that comes to mind is that in singing, we used to shun away from what was done in musical theater, pop and in rock. We used to say that is the wrong way to sing, classical being the right way to sing. We don’t believe that anymore. We believe that in all styles and genres that are done now, there are right and wrong ways to do it. People can sing very incorrectly in opera, and they can sing correctly in a modern style. So it’s all about technique, but you have to figure out the acoustic requirement for the specific genre. Opera in my view is not a style. It grew out of a requirement to get sound to a listener in a big hall. Now, with so much electronic amplification, we have a different set of requirements. So, the modern singing teachers spend much more time getting a wide pitch range. In opera, one and a half to two octaves is often enough. To do what is done now in commercial and contemporary music, you need to have three to four octaves or more, but with less dynamic range.


TVF: What is your opinion of driving up the chest voice high instead of mixing or bringing the head voice down?

IRT: Singing with a strong second harmonic was started by Ethel Merman in the first half of the 20th century. She wanted to make a sound that was more brass-like, brighter and “pingy.” So she cultivated this sound, which has now morphed into belt. In the musical theater world, singers need to have a voice that goes well with modern accompaniments. So belting is neither right nor wrong, it’s just a way of getting the sound and character you need for today’s drama.


TVF: Does that mean certain individuals are more capable of making that kind of sound than others?

IRT: Certainly there is training behind it. You have to choose different vowels than for opera. You can’t belt on a /u/ vowel, for example. You have to use a bright vowel like /a/ or /ᴂ/. All of the singers learn how to do that. If you choose the right vowel, then the acoustic pressures in the vocal tract will help the vocal folds become more efficient with that sound. But again, if you are just pressing or forcing it out then there is trouble ahead.


TVF: Does that mean the vocal folds vibrate differently in belting style compared to classical style?

IRT: A little bit more closed quotient (the relative time the vocal folds are in contact as opposed to apart). That creates more energy in the second, third, and fourth harmonics for a belt in singing or a “call” in speech. But mainly, the strength in the harmonics produced, particularly the second harmonic, comes from the choice of the right vowel. That is the key.


TVF: What do you think of the recent trend of studying the health benefits of singing?

IRT: Oh I love it! That is one of the things that our new PAVA organization really wants to stress. Vocalization is not just for getting words to another individual, but it is for general health. It makes you feel good to vocalize. It cleanses your body if you vibrate your tissues a certain amount during the day. I believe very much in that, although evidence is scarce. My greatest desire, with the rest of the time that I have, is to bring vocalization for general health to the forefront for the public.


TVF: What comes to your mind as one of the most pressing issues in contemporary voice disorders?

IRT: Those who vocalize in very minimal way seem to develop what I call a “locked larynx.” It gets cramped into one region of intensity and fundamental frequency, and people can’t get out of it. Psychological stress may add to this problem of never getting the voice out of this locked position. For that reason, I think we need to get back to calling and vocalizing with more energetic sounds.


TVF: Do you think the locked up larynx is the sort of the “egg” or precursor for muscle tension dysphonia?

IRT: I think they are highly related. You are absolutely right. Clinicians who use the laryngeal massage techniques find that some larynges are very rigid. There are small spaces between the cartilages, and the muscles only have one combination in which they function. So we need to exercise the larynx over wide ranges of pitch, loudness, and voice qualities in order to give it a chance to work the way it was designed to work.


TVF: Do you have a vocal pet peeve?

IRT: (laughs) I can’t come up with a single one. Generally, my biggest peeve is minimalism in vocalization. We are over-amplified by electronic devices. Everywhere we go, people need to have a microphone to speak in front of audience, so my pet peeve would be “put that thing down if you don’t need it and go back to using full scale vocalization in order to communicate!”


TVF: What is your opinion on the current trend of “glottal fry?” Do you think this is a vocal health hazard?

IRT: I do think that it has a potential of being a vocal hazard. That kind of sound is like “vocal texting” where there is little vocal energy and little expression in the sound. Glottal fry is produced with very little muscle activity. It’s just vocal folds flopping around without identity of a specific mode of vibration, as we call it in acoustics. There is also not much intonation in it. Melody is lacking. The fundamental frequency is so low that you never really exercise the muscles of the larynx. Most importantly, you never put any tension on the ligament. The larynx no longer functions the way it once did when we had to be in the fields or woods calling each other.


TVF: Are you aware of any literature quantifying effects of glottal fry?

IRT: We studied it on a perceptual basis several decades ago. The results are in my book “Principles of Voice Production”. NPR has been a little crazed about people expressing their likes and dislikes for it. That may lead to new research in the physiology and the mechanics behind it.


TVF: As a researcher, what keeps you on your toes?

IRT: Constantly being with people who have questions about voice and then walking (with my two Dachshunds) in the hills thinking about it. How can I answer that question or how can we move the field forward? To me, the beauty of working in the voice area is that we are not an ivory tower, academically. We are with people who are vocalizing or who are struggling with their voice. This generates new questions every day. It is exciting to go into the classroom or to a professional meeting and present what was discovered last week. That’s what keeps me going.


TVF: For people in other disciplines of science, how can they get involved in voice?

IRT: We need the tools that come from biology, engineering, physics, and neuroscience. Often we attract people from those disciplines. But we can’t keep all of them because they need to be in the field for a long while to understand our problems. They have to immerse themselves into our discipline. It’s not enough to just read a paper and say “Oh, I can do this, or I can I do this a little better”. It’s a combination of having the hard science as a background, but then really living with the people who have the questions.


TVF: What institutions right now would you recommend for people like that?

IRT: You mean young budding scientists who want to go into the voice field? Well, there have been good schools with a long history, like the University of Iowa, the University of Wisconsin, Northwestern, Purdue, Indiana, the University of Arizona, just to name a few. We found that the land grant institutions in the central part of the country adopted communication science and disorders more vigorously than the famous ivy leagues schools in the East and the famous schools on the west coast. The top-ranking schools on the coasts are great in the areas of phonetics and linguistics, but when it comes to speech-language pathology and singing, I found the biggest concentration in the middle part of the country.


TVF: Which vocal myth would you like to dispel?

IRT: There is one little one that has to do with the Bernoulli Effect! (Laugh) All the text books you read say that vocal folds slam together because of the Bernoulli Effect. That alone doesn’t do the job. In the last 15-20 years we have dispelled that myth. But unfortunately it’s still around because a lot of people read the old text books and they don’t’ really absorb the new material very fast.


TVF: I was guilty of that too. I have since converted. (Laugh)


TVF: Who is your favorite singer?

IRT: My all-time favorite singer was a tenor by the name of Fritz Wunderlich, a German tenor who sounded not at all German. He had the wonderful Italian timbre in his voice, but he had the precision and accuracy that is so traditionally German. And that combination is very rare. Unfortunately he had a very early death. He died in his mid-30s. If that voice had been around longer, we would have heard much about him. In fact, the year that he fell and fatally injured himself, he was supposed to sing at the Metropolitan Opera in the role of Don Ottavio in Don Giovanni. Unfortunately, he never made that trip. It’s sad. To me his voice was a golden voice.


TVF: What sparks “joy” for you as a person?

IRT: Being led somehow to a new discovery and never knowing how it came. I believe in inspiration. I often sit in my office thinking and pondering…nothing happens. I don’t get an answer. Then all of a sudden, one day, there is a ray of new intelligence that puts me on a different path. The greatest joy is to work it through and organize it in a way that makes other people’s lights turn on. So, basically the harmony between the discovery and the communication spark joy.