ESTIMATING PRESSURE AND VOLUME VELOCITY IN THE EAR CANAL FOR INSERT HEADPHONES

It is difficult to measure or estimate accurately the pres-sure or the volume velocity at the eardrums of human sub-jects. A method that enables us to determine both the pres-sure and the volume velocity evoked by an insert earphone in the ear canal is developed. The method can be used to accu-rately estimate pressure frequency response at the eardrum. A pair of headphones with in-ear microphones is modeled as a Norton equivalent electroacoustic volume velocity source. A custom-made new miniature particle velocity sensor is used in the modeling of the velocity source. Measurements made with the particle velocity sensor and those made with minia-ture microphones show that the presented estimation method is accurate up to 12 kHz. The method can be applied to bin-aural reproduction as well as to audiological measurements. Index Terms — Insert headphones, eardrum pressure, volume velocity