In assessing vocal fremitus the patient is asked to repeat the phrase 'ninety-nine' whilst the examiner places the palm of his hand on the patient's chest.
This procedure is repeated in different locations at the front and back of the chest. The examiner must gauge the level of vibration felt during this procedure.
Tactile vocal fremitus is increased over areas of consolidation and decreased or absent over areas of effusion or collapse. In practise it is extremely unusual to be able to detect vocal fremitus.