Voice analysis for singing teachers

Cordula Maria Ledwoch writes about her work with Overtone Analyzer:

Voice Analysis Software

The Overtone Analyzer is a software by Bodo Maass and Wolfgang Saus that has originally been developed to aid the teaching of overtone singers. It displays sound in the form of line patterns whose color (intensity), position (pitch) and length (duration) make the features of the sound visible. This allows to recognize even very small differences that an untrained listener would not be able to discern. Different adjustments of the display allow to highlight individual aspects of the sound analysis. The analysis is recorded just like a normal audio track. It can be replayed, edited, and saved in various different formats.

I have been working with Overtone Analyzer since May 2008. After I had looked at various other pieces of voice analysis software, it was almost a revelation to find how easy it is to use this one. I am what you could call computer dyslexic, and usually I need a lot of time and tuition from experts until I can do something useful with a new software application. The basic functions of Overtone Analyzer are as easy and logical to use as a simple tape recorder.
In spite of its simple operation, Overtone Analyzer is very flexible in its possible settings. I can use the various functions many combinations, and I can minimize or ever completely hide unused features.
I can adjust the resolution of the image independently along the time axis and the frequency axis. The many different color schemes allow to present the image either very scientifically, or almost artistically beautiful. Depending on the current focus of my work with a singing student, this can be an important (but very subtle) means of psychological support.

Recording Voice Lessons

As a singing teacher I was already used to record my lessons at the students' request. Hence I have just switched to a different recording system. The only thing I still needed was a good USB microphone (cost: about 80 Euro).

I generally recommend to record voice lessons because it frees the singing student from taking written notes whilst still allowing to review all exercises and developments of the lesson later. It also allows me to retrieve recorded lessons from the archive (in the absence of the student) and search for strategies for specific problems.
Using Overtone Analyzer has the added advantage that I can stop the recording at any point during a lesson and replay a section repeatedly. The time line at the top allows to click on other parts of the lesson and to play them for comparison.

Letting students see what they sing

Most singing students are quite excited during voice work. This distracts them  from perceiving the fine differences in sound and color of their voice during singing. This is particularly true for beginners and very young people. Through Overtone Analyzer I can immediately pinpoint an improvement and reinforce it. This allows the student to recognize the improvement clearly and to remember the means to achieve it.

Complementing the teacher's refined ear

A singing teacher usually has a very fine ear because of his training and years of teaching experience, which gives him a good ability to discriminate pitch, frequency shifts and texture changes in the voice. In that sense he hears multi-dimensionally. Because of this I don't really need this program to do my work as a singing teacher well. But using Overtone Analyzer has still helped me to verify the many small perceptions that happen more instinctively than consciously in a voice teacher. To my great surprise, I discovered clearly visible differences when analyzing singing mistakes of my students, even when I perceived those mistakes as minimal. This visual feedback has greatly refined my confidence in recognizing problem areas and the accuracy of my analysis.

At the same time, this also allows me to solve another problem when dealing with my students:

Gaining the trust of the student

A beginning student doesn't have the skill of acoustic analysis at the onset of his training and needs to trust me blindly. Usually it takes quite a while until a new student knows me well enough to give me his unconditional trust. I now use the Overtone Analyzer as „translator“ of an acoustic pattern into a visual one. Since most people are much better at visual analysis, the student can now more easily recognize the important differences (similar to how most untrained people can immediately spot weave flaws or color changes in a piece of fabric).

Building confidence

When seeing his sound in parallel to hearing it, the student is able to understand the tonal pattern much faster than normally. This allows a very fast development of the acoustic imagination and analysis and enables the singing student to become autonomous in his judgment. This builds his confidence when practicing or singing without the teacher. He can use his own perception as a guide instead of depending on the gestures and expressions of his teacher like a trained parrot. The acoustic pattern that has been translated into a visual one by Overtone Analyzer can now increasingly be transformed into a tactile one. This accelerates the learning process enormously.

Accepting praise

Another problem that I'm often confronted with as a teacher is the hypercritical way in which many students regard their own voice. Especially experienced singers that come to be coached, or students that are already older when they start singing lessons, tend to be suspicious when I praise them (perhaps they suspect that I only praise them to make them feel comfortable so that they stay with me). Overtone Analyzer allows me to substantiate any assessment that I make with measurable facts. For example, I can immediately show if the pitch of a tone was correct. And with the loop function I can repeat the sung tone until the student can hear it himself. Hence he doesn't need to trust me, but only his own senses. After he has experienced a few times that my hints are correct, he is usually also able to accept praise. This also increases the speed of learning.

A neutral observer

Voice work is always a confrontation with the own personality (soul). This is very intimate and often highly emotional. A criticism of the voice is easily felt as criticism of the person, especially by emotionally insecure people. This creates so much fear in such students that they tense up and become discouraged. Some even give up their singing training altogether. If not, then they still often are tense and at the verge of panic. Some students in this phase exhibit a sad or desperate mood, others can be almost hysterically cheerful and silly. It is difficult to help such students, because the teacher needs to consider his every word with extreme caution.

In these cases I use the Overtone Analyzer as a „scientifically neutral“ observer with which we analyze the voice together. I let the singer sing a short sequence or exercise and ask him to sing one version as usual, and then to repeat it with my suggested correction. Then we play back both versions a few times and I ask the student what he himself hears and sees. Through this game the student notices his mistakes himself and learns to assess himself realistically. Usually after a short time he also learns to better control his fears and then he can also trust me more. Whenever he becomes insecure again I return to this kind of work, which is especially effective with students that have made bad experiences with teachers that were unsystematic or too strict. This approach quickly brings some small successes that encourage the student to persevere. It used to require half a year (or more!) until a new student had fully arrived. Now this usually takes at most two months.

Painting with the voice

Even with confident students or experienced professional singers this approach of visualizing the voice increases the „fun factor“ considerably. It's like „painting with the voice“. Many start to spontaneously experiment with techniques that they would not use by themselves. This enables me to even teach giggly 13-year-olds on a high level without them getting bored or perceiving the lesson as work. Sometimes I even have to ask them to leave because they still want to try something out, while the next student is already waiting.

It is certainly possible to give the student such a (possibly simplified) sound analysis software for use at home. But in my opinion this is not necessary to achieve the described learning effects. In my experience the use of Overtone Analyzer during voice lessons and the confrontation with the facts is sufficient to create a lasting impression. On the other hand, advanced students could benefit from the software to monitor themselves during their daily practice.


To me, one advantage of using Overtone Analyzer is the enormous time saving. First, this applies to the amount of time I need to gain the trust of the singing student. Second, it greatly reduces the time needed by the student to recognize mistakes and to implement the subject matter.

Another advantage of the program is the precision of the voice analysis and the flexible adjustment of the display, the functions (and their combination) and the saving of the recording. A further advantage is that the program requires very little time, both for the initial period of learning its operation, and later for actually using it during voice lessons.
A final advantage is the comparatively low cost. I just need an average office PC and a USB microphone. I can save the recordings on an external harddrive when I need them in the wav format. As mp3s they even fit on the internal harddrive. Compared to some scientific sound analysis programs, Overtone Analyzer is relatively inexpensive (and there are even some lower priced editions). With this equipment I have a recording function, a cutting table, a visualization and a (scientifically correct) sound analysis.


Cordula Maria Ledwoch is a Soprano and Singing Teacher in Cologne, Germany