Résumé
Objective To study the relationship between pulsatile tinnitus and temporal bone pneumatization grade. Methods Through the in vitro experiment, the generation and transmission pathways of the venous sound were simulated. The sound signals at the position of eardrum were recorded and analyzed. Results In case of cortical plate dehiscence, the high pressure and pulse-synchronous venous sounds were received at eardrum. The highest sound pressure occurred in the normal pneumatization case. In case of cortical plate intactness, the non-pulsatile venous sounds with pressure close to the background control sound were received at eardrum. Temporal bone air cells (TBAC) with different pneumatization grades would transmit venous sound in different frequency ranges. Conclusions Normal pneumatization TBAC exhibited the highest amplification on venous sound, while hypopneumatization TBAC exhibited the lowest amplification on venous sound. The pneumatization grade of TBAC is neither the sufficient nor essential condition of pathogenic venous sound, while the cortical plate dehiscence is the sufficient or necessary condition of pathogenic venous sound.