Tactile or vocal fremitus is the palpable vibration you feel when the patient speaks (says ‘99’).
Assessment of tactile fremitus is used to evaluate airflow and density of underlying tissue. Normally, the thicker the chest wall, the more diminished the fremitus; the lower the voice pitch, the greater the fremitus.
Increased fremitus (low voice pitch): conditions causing fluid or exudates in lungs (e.g consolidating pneumonia, atelectasis, pulmonary fibrosis, pulmonary edema, or pulmonary infarction) and sometimes lung tumor depending on size and mobility.
Decreased or absent fremitus (high pich): air trapping, solid tissue, or decreased air movement (e.g. emphysema, asthma, pleural effusion, pneumothorax, or distal to airway obstruction)