Analyzing Research on Register Transitions

Lately I've been on a bit of a kick, writing some straight up vocal science posts that are making me happy. I love me a good research article! This week I thought perhaps it could be fun to go through a paper together on a rather tricksy topic: register transitions in trained sopranos.


It can be a bit of a daunting task to go through a paper. There's a language in the research world that is not always exactly like how a regular human would talk. This is on purpose, because by using precise language, even when it is full of jargon, ideas can be communicated more clearly. If you speak the language of science, that is. Learning to speak that language can be a bit of an uphill climb, but for many of us who love singing and love the "why" behind singing, it can be worth it to try.


First off, here's the paper I'm going to take us through today: "Laryngeal evidence for the first and second passaggio in professionally trained sopranos" by Echternach, et al. When you click on the link, you'll get to a webpage that has the whole article, and on the right of the page is a button that says "Download PDF," if you'd rather have that. Since this is open access (THANK YOU, AUTHORS!), we can get it for free.


How I read a research paper


I don't usually read a paper from the start to the end, straight through. You can certainly do it that way, but I've found a system that works for me a little better. (For a quick overview of the parts of a research paper, here's a blog I wrote on it a while back: Reading Research, Part 1.)


When I read a paper, I usually do it in this order:

  1. Abstract

  2. Results and Conclusions

  3. Discussion

  4. Methods

  5. Review of Literature/Introduction

It's almost reading from the end to the beginning. I do this because it helps me to know where the authors are going as they are building their argument. All research papers are presenting an argument, of sorts. That's not to say they are being confrontational. Rather, they are saying, "This is what I think is happening under these particular circumstances, and here is why I think that." The paper is laying out the way to get from the question to the answer. It helps me to know what the authors think the answer is, then I go back and see if they laid out their case well. Other folks would read a paper differently, and that's fine. This is my system, so find what works best for you.


What is happening in this paper?


When I read the abstract, I see that the authors are trying to determine if there is something physiologically happening as these singers go through their upper and lower register shifts, called the passaggio. In this observational experiment, the study authors asked ten trained female sopranos to sing ascending vocal slides in two octaves. They then collected data using stroboscopy and an electroglottalgraph, or EGG. Twelve people listened to the recordings and indicated where they heard the register shifts happening. When comparing where the listeners heard the register shifts occurring with what was happening on the EGG and on the video of the stroboscopy, the authors noted that vibratory patterns were different. So, they conclude that something is happening physiologically, and they offer two possible hypotheses for what is going on.


When I go to the end of the paper, I read in the Results section that there was a problem with the data collection on one of the singers, which is not uncommon. Sometimes with this kind of equipment, you don't know if it's really working until everything is said and done and you download the data. Ask me how I know...


But then, there's some surprising results. Even among only 10 singers, there were differences in how the vocal folds were behaving. In other words, one might expect that with a similar singing task, ten singers would have similar vocal fold vibratory patterns. But of course they didn't, because nothing in singing science can be simple. LOL. The Conclusions chapter reiterates that something is happening physiologically during register transitions, but more research is needed to identify what and why. Fair enough.


Backing up a bit to the Discussion section (my favorite part to write and to read), the authors state rather cheekily that not all the singers performed a smooth register transition while singing their pitch slides. I would challenge any researcher to do a perfect job of singing with a camera down their nose and an EGG strapped on to their neck, but that is also the nature of research in a lab setting. It's just weird, y'all. But for those singers that had a clunkier register shift, they had an understandably larger shift in the vibratory pattern of the vocal folds. That makes sense.


Through the rest of the Discussion, the authors look at each of the results they found and try to "write out loud" why they think those things occurred. They talk about the limitations of data storage that made them stick with one-second glides, rather than a longer phrase that is probably more close to what singers would really do on the stage. Data limitations are real, too, and I think these authors did a decent job of trying to get around those. I personally find this section to be very well written, and they do a good job of highlighting both the positive and the negative aspects of their method. A good scientific writer will do this, and it's executed well here.


Speaking of the Method, this is the next part of the paper I would read. I start off with the Results first, because then when I go back to read the Method, it gives me a better idea of whether the authors could actually reach the conclusions they did using the method they designed. If they have some conclusions, but the method is not leading to those conclusions, I question things more.


A well-written Method section will give you enough info to be able to replicate the experiment with very little trouble. And so this section can be super dry and very technical. You'll often find the exact equipment used, down to the model numbers and manufacturing information, as well as a nearly step-by-step walk-through of how the data was collected, stored, and analyzed. We also see who the participants were, in an anonymous fashion, and often how they were recruited.


This Method section is pretty clear, and I think the experiment they set up supports the results they found. There aren't any steps that call their results into question. In other words, there's no need for any big logical leaps to get from the experiment to the results. That's very good.


What does this paper tell me about teaching singing?


First, no surprise, register shifts are tricky. They tend to be trickier for more inexperienced singers. And so that tells me that when teaching register transitions, patience is going to be key while the anatomy learns what to do. Most of us probably already knew this, but having data to back it up is nice confirmation.


Second, there's not one right way to do a register shift. There were four changes observed in these ten singers, and it might not make a bit of difference which strategy is used, as long as the job gets done. And depending on the day and the experience of the singer, more than one physiological strategy could be needed. It would be very interesting to do a repeat study with a few singers to do the same thing multiple times over multiple days over the course of a few weeks or months, and see if singers use the same strategy all the time, or if they change it up. In the studio, try a lot of strategies to see what sticks, and perhaps try multiple things so singers have options when they need them.


Third, even with a bunch of fancy equipment and stuff, relying on a teacher's ears to hear what is going on is still very much needed. There's no danger any time soon of you being replaced by a robot who will teach singing. Your expert ears are a vital part of the process.


Last, there is a still a lot of mystery in singing. We can sometimes observe what is happening, sometimes we don't yet have the equipment that is refined enough to do so. We can't always discern the "why" behind the "what" all the time. I think this mystery is both frustrating and inspiring. Frustrating because of course we want to know why things are happening, but inspiring because the voice is so complex that it's amazing how many times it just works without a second thought. I'm never going to get bored!


Conclusions


If you stuck with me this far, congrats! I hope you maybe gained a bit of insight into how to read a paper, or maybe just had a little fun going through one today. If this is the kind of thing that lights your fire, there's tons more where this came from! We can go through papers together during a Vocal Ped Party, looking at what the authors wrote and how you can apply that research to your own teaching. If you're ready to try that out, book some time with Your Personal Pedagogy Professor below. Research can be accessible and even fun!


Resources:


https://www.drheathernelson.com/post/a-short-ish-primer-on-reading-research-part-1-getting-research-into-our-hot-little-hands


https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175865#:~:text=In%20both%20the%20first%20and,loss%20of%20vocal%20fold%20contact.