Method for the recording of acoustic parameters for the customization of hearing aids

1. Method of measuring an impedance of an ear canal comprising the steps of:

measuring a first sonic pressure with a first pressure microphone;

determining a sound energy flux by the difference of the measured first sonic pressure in relation to a second sonic pressure measured with a second pressure microphone through a calibrated acoustic resistance; and

calculating the impedance from said first and second sonic pressures.

2. Method according to claim 1 wherein the calibrated acoustic resistance comprises porous sinter bronze arranged concentrically around a channel of the first pressure microphone.

3. Method according to claim 1 , wherein the step of measuring is performed by pressure microphones arranged in a hearing aid shell, and wherein the hearing aid shell is introduced into the ear canal before starting the step of measuring.

4. Method according to claim 3 wherein the step of calculating comprises evaluation of signals from said first and second pressure microphones by electronic components arranged in the hearing aid shell.

5. Method according to claim 1 further comprising the step of implementing curve fit proceedings onto the measuring results, to calculate or estimate the following parameters:

impedance, and/or

effective distance of a hearing aid outlet to an eardrum, and/or

compliance of a rest volume of the ear canal, and/or

overall compliance at deep frequencies, and/or

individual transitional function of an inner ear, and/or

effect of leaks.

6. Method according to claim 1 wherein the measuring is made under variable, adjustable static pressure in the ear canal.

7. Method according claim 6 wherein the static pressure is adjusted over an additional static pressure line for the ear canal.

8. A measuring device for performing a method of measuring an impedance of an ear canal comprising:

a first pressure microphone measuring first sonic pressure;

a second pressure microphone for measuring a second sonic pressure through a calibrated acoustic resistance;

means for determining a sound energy flux by the difference of the measured first sonic pressure in relation to the measured second sonic pressure; means for calculating the impedance from said first and second sonic pressures; and

a probe adapted to be at least partly introduced into the ear canal, wherein said first and second microphones are arranged within the probe, and wherein an acoustic resistance is pre-connected to at least one of said first and second microphones.

9. Measuring device according to claim 8 wherein the calibrated acoustic resistance comprises a porous sinter bronze.

10. Measuring device according to claim 8 arranged within a shell of a hearing aid adapted to a shape of the ear canal, and comprising evaluation electronics arranged within the shell and connected to said first and second microphones of the measuring device.