Abnormal
nasal resonance is frequently observed in the speech
of deaf individuals. Students may have an overall
resonance pattern characterized as nasal or denasal
or they may have specific problems coordinating articulatory
gestures with valving of the velar-pharyngeal port.
Distorted nasal resonance may be attributed to
faulty control of velar-pharyngeal closure and/or
to faulty movement and positioning of the tongue
for vowel production. Both result in an altered
resonance cavity that distorts the acoustic signal.
Some surmise that this faulty resonance enhances
proprioceptive feedback.
It is often difficult to determine how a student
is creating a particular resonance pattern. This
makes remediation a challenging and difficult task,
especially if the student is unable to capitalize
on auditory feedback to monitor performance.
We have found that students may utilize visual
feedback regarding acoustic characteristics of their
speech. For example, they may see a dampening of
acoustic energy or distorted harmonics on a speech
spectrogram. They may also use a spectrogram to
monitor faulty articulatory gestures. The following
examples illustrate these points.
