Method and apparatus for fitting of a hearing aid and associated probe with distance measuring means

• US 5,044,373 A
• Filed: 01/24/1990
• Issued: 09/03/1991
• Est. Priority Date: 02/01/1989
• Status: Expired due to Fees

• Current Assignee: GN Danovox A/S
• Original Assignee: GN Danovox A/S
• Inventors: Northeved, Allan, Johnsen, Torsten
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Pontius, Kevin
• Application Number:
  US07/469,221
• Time in Patent Office: 587 Days
• Field of Search: 128/746, 181/130, 181/135
• US Class Current: 600/559
• CPC Class Codes: A61B 5/121 evaluating hearing capacity
• CPC Class Codes: H04R 25/502 using analog signal processing
• CPC Class Codes: H04R 25/70 Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting

Abstract

The invention relates to the measuring of sound pressure levels in the auditory canal of a person in connection with the fitting of a hearing aid. An apparatus for this purpose comprises a measuring probe (1) which is introduced into the auditory canal, a microphone (6) coupled to the measuring probe (1), a data processing unit (14) with display (15) and printer (15'"'"'), a reference microphone (8) and a source of sound (10). In order to be able to position the measuring probe (1) precisely in the auditory canal, the probe is configured with means for measuring the distance from the free end of the probe to the ear drum which employs either sound, electromagnetic waves or light.

Claims

1. Method for the fitting of a hearing aid to an ear, whereby:

a) an acoustic signal in the audible range is applied to the ear,

b) the sound pressure at the inlet to the outer ear is measured, the result of said measurement being used for adjusting the amplitude of the applied acoustic signal,

c) the sound pressure is measured at a position in the vicinity of the ear drum using a measuring probe comprising a tube having an end inserted in the auditory canal, and with open ear,

d) the sound pressure is measured at said position in the vicinity of the ear drum and with said measuring probe, but with a hearing aid device place correctly in the ear,

e) the sound pressures measured under c) and d) above are fed to an electronic circuit for the formation of the difference between the sound pressure measured with the hearing aid device and the sound pressure measured without the hearing aid, said difference being used for the adjustment of the hearing aid device,

characterized in that the measuring probe tube end comprises means for the measurement of the distance between the probe tube end and the ear drum, said measurement being carried out by the emission of light and the receiving of reflected light, in that the distance measurement is effected by scanning he time difference between the emission and reception of the light with a measuring circuit for the distance measurement.

2. Method according to claim 1, wherein said hear aid device comprises a hearing aid sounding body.

3. Method according to claim 1, wherein said measuring circuit comprises signal elements.

4. Method according to claim 1, wherein said measuring circuit comprises display elements.

5. Apparatus for use in the fitting of a hearing aid and comprising:

a) a signal source (10) arranged to emit an acoustic signal in the audible frequency range,

b) a reference microphone (8) for the measuring of the sound pressure created by the signal source at the inlet to the user'"'"'s ear, and with means (14) for the regulation of the strength of the signal source,

c) a measuring probe (1) comprising a tube having an end inserted in the auditory canal, with microphone for the measurement of the sound pressure in the vicinity of the ear drum (3),

d) a data processing unit (14) for the calculation of the measured sound pressure levels, characterized in that the measuring probe (1) tube end comprises means (21,

     29) for the measurement of the distance between the probe tube end and the ear drum comprising a light source with means for conducting light to the measuring probe tube end, means for receiving light reflected off of the ear drum and conducting the reflected light to a measuring circuit for calculating the distance between the tube end and the ear drum by measuring the time difference between emission and reception of light from the light source.

6. Apparatus according to claim 5, characterized in that the means for conducting light conducts light forwards (20) in the probe'"'"'s axial direction, and not substantially outside the extension of the outer periphery of the probe, and that the means for receiving and conducting reflected light is directed substantially in the same direction.

7. Apparatus according to claim 5, characterized in that the measuring circuit (29) further comprises means (30, 31) for producing signals when the probe (1) tube end is at a certain distance from the ear drum.

8. Apparatus according to claim 5, characterized in that the measuring circuit (29) further comprises a calibration element (34, 35) for the adjustment of the measuring accuracy of the means for the measurement of the distance between the probe tube end and the ear drum.

9. Apparatus according to claim 5, wherein said light source produces light which is pulse modulated.

10. Apparatus according to claim 5, wherein said means for conducting light is secured to the measuring probe tube end.

11. Apparatus according to claim 5, wherein said means for conducting light is disposed inside said measuring probe tube.

12. Apparatus according to claim 5, wherein said measuring probe further comprises an amplifier for measuring the sound pressure in the vicinity of the ear drum.

13. Apparatus according to claim 5, wherein said data processing unit further comprises a display means for displaying the measured sound pressure levels.

14. Apparatus according to claim 5, wherein said data processing unit further comprises a printer means for printing the measured sound pressure levels.

15. Probe apparatus for use in the fitting of a hearing aid during the measurement of the sound pressure levels in the auditory canal of a person, characterized in that the apparatus comprises at least one tube (22, 25, 26) having a free end and means (21) for conducting light distance measurement signals from a measuring circuit (29) to the tube'"'"'s free end and reflected light signals in the opposite direction, in that both the tube and the means, at an end which is opposite the tube'"'"'s free end, are secured in a holder (36) which is arranged to allow the tube and the means to be coupled to the measuring circuit (29) as a replaceable unit.