Lead Article: An Intuitive Vocal Fold Functional Model for Modal Voice Phonation for Use in the ENT Voice Clinic

Abstract

Routine voice assessment by acoustic analysis can be of substantial value to clinical examination in the ear, nose, and throat (ENT) voice clinic. Improved functional diagnosis, more informative patient records, accurate assessment of patient progress and better clinical team liaison are but a few of the benefits realised over a decade of work in the Edinburgh voice clinic. To obtain these advantages through instrumental voice assessment, it is important to have a thorough understanding of what is being measured and the reason behind the measurement. It is also vital to remember that acoustic measurements can be directly related to vocal fold function but not necessarily to pathology. To interpret analysis results, it is therefore important to possess a functional model for vocal fold phonation which relates vocal fold mechanics to what is seen, heard, and measured in the voice clinic.

This article describes vocal fold function using intuitive concepts which have assisted the multidisciplinary voice clinic team in Edinburgh. This intuitive model, which describes the biomechanical phonatory function of the vocal folds, has added meaning to the routine computer-supported measurement protocol used for 4 years in our voice clinic. the model enables the assessment of vocal fold function and has been of considerable benefit to the performance of the clinical service. Clinical emphasis has moved towards evaluation of the acoustic function of the free mucosa, presence band spectral enhancement, and particular emphasis on modal voice. Significantly, this perspective comes not from academic research, but from routine hospital experience involving over 3,000 patients.