Tactile Fremitus, is a vibration felt on the patient’s chest during low frequency vocalization. Commonly, the patient is asked to repeat a phrase (eg, ‘Ninety-nine’, ‘boy oh boy’) while the examiner feels for vibrations by placing a hand over the patient’s chest or back. ‘Ninety-nine’ however is a misinterpretation of the word “Neun-und-neuzing” that was used in the original German report which was the low-frequency diphthong of choice.
Tactile fremitus is normally more intense in the right second intercostal space, as well as in the interscapular region, as these areas are closest to the bronchial bifurcation. Tactile fremitus is pathologically increased over areas of consolidation and decreased or absent over areas of pleural effusion or pneumothorax.
The reason for increased fremitus in a consolidated lung is the fact that the sound waves are transmitted with less decay in a solid or fluid medium (the consolidation) than in a gaseous medium (aerated lung). Conversely, the reason for decreased fremitus in a pleural effusion or pneumothorax (or any pathology separating the lung tissue itself from the body wall) is that this increased space diminishes or prevents entirely sound transmission.
It has recently been suggested that the artifacts caused by eliciting tactile fremitus during breast ultrasonography can be used to differentiate between benign and malignant tumors.