Electric acoustic stimulation

In several clinical studies, EAS has proven to yield superior results compared to partially deaf patients who use only hearing aids.

The concept of combining simultaneous electric-acoustic stimulation (EAS) for the purposes of better hearing was first described by C. von Ilberg and J. Kiefer, from the Universitätsklinik Frankfurt, Germany, in 1999.

This group only receives limited benefits from traditional amplification because of the severity of the hearing loss in the high frequencies.

The residual median hearing preservation for children was identified to be better when perimodiolar electrodes were inserted with AOS through fenestral cochleostomy.

The best results have been achieved with electrode insertion depths of 18 mm, which corresponds to the approximate place in the normal sized cochlea where 1000 Hz is processed.

The design of the electrode array (shape, length, and bundle flexibility) is one of the key factors for preserving residual hearing.

The direct transmission improves the sound quality for the user, making it easier to, for example, talk on the phone or stream music.

All three major EAS manufacturers offer various ALD options, including direct connectivity to Bluetooth-enabled devices.