Cochlear Microphonic Potential Phase Shift (DPMC)


With its knowhow and its collaboration with the Clermont-Ferrand Sensory Biophysics Laboratory, ECHODIA Company developed a Cochlear microphonic potential phase shift measure (DPMC). This world exclusive measurement belonging to ECHODIA, records the response time from external ciliate cells of the cochlea, electrophysiologically, following an acoustic stimulation called toneburst. Our exclusive clinical studies have shown that the measured time is the image of the pressure in the perilymph (base). Monitoring DPMC can observe reproducible or isolated pressure changes from the cochlea and thus highlight a cochlear hydrops.



User tips: 

- Make sure that the ear canal is not obstructed by a wax plug.

- Clean the surface of the skin where the electrodes will be attached with abrasive gel. This decreases the impedance of the skin.

- The patient must be settled comfortably to avoid any excessive muscle tension.

- Use of saline water is recommended to improve the conductivity of the ear.


Measure specifictions:

- Acoustic stimulation from 900Hz to 1100Hz

- Specific headset

- Impedance tests

- Configurable rejection

- Sound intensity from 40 to 90dB SPL


Aimed Diseases

- Hydrops.

- Vertigoes.

- Non-invasive diagnosis of the Ménière’s disease.



The cochlea, peripheral organ of hearing, contains the external ciliate cells (ECC) which have a role in amplifying acoustic signals through their contractile properties. By applying acoustic stimulation to the ear, particularly a tone burst (1kHz frequency), it will stimulate the sensitive part of the ECC at this frequency.

The ECC will thus be stimulated to contract in resonance with the same frequency as the stimulation frequency (1 kHz). As a muscle contraction ECC generates an electric specific potential: Cochlear Microphonic Potential (CMP).

In healthy subjects as subjects with endolymphatic hydrops, a postural test (transition from standing to lying down) causes an increase in intra-cochlear pressure (exaggerated in the context of Meniere's disease). Indeed, during the postural test, there is a change in the distribution of the cerebrospinal fluid that spreads to the cochlea via the cochlear aqueduct. Monitored for some time, the physiological parameter cochlear allows real-time monitoring of the intra-cochlear pressure change. 


Echodia device allowing DPMC measurements: ELIOS.