[2] This is usually assessed with the healthcare provider placing the flat of their palms on the chest wall and then asking a patient to repeat a phrase containing low-frequency vowels such as "blue balloons" or "toys for tots" (the original diphthong used was the German word neunundneunzig but the translation to the English 'ninety-nine' was a higher-frequency diphthong and thus not as effective in eliciting fremitus).
An increase in tactile fremitus indicates denser or inflamed lung tissue, which can be caused by diseases such as pneumonia.
[2] Pleural fremitus is a palpable vibration of the wall of the thorax caused by friction between the parietal and visceral pleura of the lungs.
As a test to determine the severity of periodontal disease, a patient is told to close his or her mouth into maximum intercuspation and is asked to grind his or her teeth ever so slightly.
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 been suggested that the artifacts caused by eliciting tactile fremitus during breast ultrasonography can be used to differentiate between benign and malignant tumors.