The patient is asked to repeat the phrase 'ninety-nine' whilst the examiner listens over his chest with a stethoscope.
If there is consolidation in the area of lung over which the examiner is listening, there will be increased vocal resonance. In this case the numbers will become clearly audible. Over normal lung the numbers are normally muffled. Vocal resonance may be so great that whispered speech may be distinctly heard (whispering pectoriloquy).
Note that over consolidated lung there is an increased transmission of high frequencies and speech heard through the stethoscope may take on a bleating quality (aeogophony - goat voice).
Vocal resonance may be decreased or absent in the presence of effusion or collapse.
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.