Vocal Capability Battery
This portion of the exam actually starts during the history interview as many cues can be picked up during conversation with the patient. Then a series of vocal behaviors are elicited from the patient and recorded. The reason for performing these tasks are that they are a vocal stress test. Like the more familiar cardiac stress test, many problems show up under exercise. The speaking voice is typically near the lowest end of the patient’s pitch range and using the speaking voice could be likened to measuring the hearts ability to pump while sitting down at rest. Asking the patient to phonate throughout their range then would be like exercising. A generalization is that most voice disorders cause problems with stiffening the vocal fold and are most detectable at high pitch when extra physiologic stiffness is being applied to the vocal folds. Neuromuscular problems are typically best detected at lower pitches when the additional physiologic flaccidity augments any preexisting muscular problem.
This portion of the exam is audio recorded for documentation and later review.
- Speaking voice
- Maximum phonation time (MPT)
- Speaking loudly
- Yelling
- Pitch Range
- Sustained pitch
- Swelling tests
Speaking voice
Anchor pitch is the lowest common pitch during a given task. We use a reading task. The patient states his/her name and reads a paragraph. In our clinic the paragraph «Mans First Boat» is utilized. It is approximately a 4th grade level of reading. There are other phonetically balanced paragraphs in use as well. It is probably most important to be internally consistent by using the same text each time. When the patient cannot read or cannot speak English we resort to counting in the patients own language. While the patient is reading we match their most obvious lowest pitch and note this as their anchor/speaking pitch. This should be considered their fundamental frequency (Fo). A typical Fo for men is about C3 or 100 Hz. A typical Fo for women is about G3 or 200Hz. See a discussion on measuring pitch.
Maximum phonation time (MPT)
We ask the patient to say /i/ (which can be translated as a prolonged eeeeee sound) at their anchor pitch. Typically they will need to be reminded that it is low in their voice. We try to use their anchor pitch to make the maximum phonation time as consistent as possible between exams, at least for a given patient. They are asked to breathe in fully and hold /i/ at anchor pitch for as long as possible. This is a very imprecise measure because variables other than pitch, such as degree of loudness or pressed phonation, can drastically affect the MPT. However, it is a useful measure in a given patient when measured before and after treatment, particularly when dealing with air wasting disorders.
Speaking loudly
The patient rereads the paragraph in their loudest possible voice. Some coaching is necessary since some patients will be hesitant to embarrass themselves since they know their voice is limited and may not sound well to others. Non organic patients will have difficulty with this unexpected task. Underdoers may have a restrained quality.
Yelling
We ask the patient to say Hey! as if they had an emergency and had to get someone’s attention. Disorders which cause a flaccidity of the vocal fold, such as paralysis or atrophy will lack an edge to the sound or, if more severe, have the characteristics of a leaky valve. The harder the vocal fold is driven, the louder will be a luffing or fluttering sound. This sound will be apparent, especially at low pitch, since the additional energy imparted to the vocal fold combined with its flaccidity will cause the fold to buckle out rather than to draw in. At higher pitches this luffing may disappear as tensioning of the vocal folds increases the ability of a flaccid vocal fold to recoil.
Non organic disorders will typically demonstrate an unusual pattern such as the voice getting softer instead of louder during a yell.
Pitch Range
Pitch range determinations almost always require coaching since singers with voice problems are embarrassed when they cannot get their voice to perform properly, perhaps even threatening their career. The rest of the world, who are shower or car radio singers only, are sometimes quite reluctant to sing in front of an audience, even as small as one person - the examiner.
To confirm range we listen for characteristics of a vocal ceiling and vocal floor to determine overall pitch range. A muscular ceiling has a tight, strained quality. A mucosal ceiling has a breathy quality. A rapport ceiling has a completely normal sound. Ceilings tend to be the same for different vocal tasks so when several tasks reveal the same pitch, the upper range has been determined.
For the ceiling, the patient is asked to sing /i/ repeating the pitch of the examiner. Often we try working up the scale by intervals such as Do Mi Sol Do. Another method is to have the patient make a sound like a siren striving to reach the highest note possible. Above C5 we may switch to /a/ or if the patient is having difficulty we switch to /oo/. We verify the ceiling by asking the patient to sing the first phrase of Happy Birthday, again working up the scale until a ceiling is reached. A staccato task is also useful for confirming the pitch ceiling.
To determine the floor of the pitch range, the patient is asked to lower their pitch in a stepwise fashion. We ask them to keep going until we hear vocal fry (a popping sound like grease in a frying pan), they can’t move lower or the sound becomes breathy. Then they are asked to try to reach their lowest note by gliding down in pitch from a mid-range starting point.. In some pathology the anchor pitch is often right at the bottom of the pitch range. The normal recoil position of the vocal folds should be 5 to 6 semitones higher.
Much pathology is revealed in the upper pitch range so this is an extremely important part of the vocal exam. The accuracy of the examiner is increased by having the patient perform multiple tasks and verifying that the extremes are the same in each task.
We utilize musical notation to describe pitch range. Middle C on the piano is called C4 (the beginning of the fourth octave on the piano). One advantage to using musical measures is the ease of communication with singers. See swelling tests below. It is possible to use Hertz as well.
Sustained pitch
The patient is asked to match a pitch and hold a prolonged phonation. Voice quality and steadiness can be observed. Characteristics may differ at different pitches. Note may be made of pitch variability, including its regularity of variation. Tremor and spasmodic dysphonia are differentiated by this test. Scarring or stiffness may also be suggested by loss of phonation throughout some portion of the pitch range.
Swelling tests (1)
Vocal fold swellings cause a very characteristic ceiling effect. Two sung phrases are utilized in our clinic. The first phrase of Happy Birthday and a staccato passage (Fig 2). These are sung by the patient in a pianissimo boy soprano style. As pitch is increased, a ceiling will be reached. A mucosal ceiling will be characterized by onset delays (air escape prior to phonation) and ability to overcome the ceiling by driving the voice or increasing the volume. A muscular ceiling will be evident by a slight flatting or straining of the pitch
Observing the patients voice at high pitch is essential for finding disorders that cause stiffness of the vocal fold. Physiologically pitch is increased by stretching the vocal fold and this physiologic stiffness adds to any lesion induced stiffness to stop or distort vocal fold vibrations. Thus, a lesion with minimal stiffness will show up as a loss of high, soft singing. As the lesional stiffness increases, the voice becomes pathologic at lower and lower pitches. Since the speaking voice is typically at the bottom end of a patients pitch range, it takes a significant amount of stiffness to cause a disordered speaking voice.
Swelling tests can be taught to patients and can be essential in preventing recurrence of nodules and polyps. The patient is taught to use the tests as a monitoring device. If they use the tests daily, they can catch swelling and alter their behavior before the swelling becomes chronic and permanent.