Patent Application
20070258609
The present invention is now described in more detail with reference to the appended drawing, which shows a flow chart of the method according to the invention.
The exemplary embodiment described in more detail below represents a preferred embodiment of the present invention.
To determine a correct target amplification and/or a correct family of target amplification curves, the pure-tone audiometric data is generally initially measured in the form of a bone conduction and an air conduction hearing threshold. Both hearing thresholds spectrally reproduce the volume level which can still be perceived. The top left of the FIG shows the measured air conduction hearing threshold Lm and the measured bone conduction hearing threshold K. Both hearing thresholds run essentially parallel to one another. The bone conduction hearing threshold Km only differs at one point, which suggests a mismeasurement. To reduce the frequency of mismeasurements, a prior examination and correction of the bone conduction values are thus carried out in accordance with the invention.
To smooth or correct the bone conduction hearing threshold in accordance with the invention, advantage is taken of the knowledge that the number of pathological changes to the middle ear leading to a sound conduction hearing impairment, which is reflected in the bone conduction, is transparent. Furthermore, the influence of the middle ear changes on the bone conduction hearing threshold is known as far as possible in each instance in terms of type, degree and pattern. An assignment to a known clinical picture having a typical pattern of the bone conduction threshold or a combination of two or more causes can thus be carried out on the basis of the existing bone conduction values. After said assignment, the outliers of the bone conduction measurement can be corrected and the target amplification curves can be calculated using the modified data.
In the concrete example in the FIG, a database having bone conduction and air conduction hearing thresholds and respectively sound conduction components for a number of hearing loss categories, each representing a specific pathological clinical picture, was recorded with its typical spectral patterns. By way of example, in the case of a first hearing loss category HK1, the bone conduction hearing threshold K1 and the air conduction hearing threshold L1 approximate to one another in the high frequency range. In the case of a second symbolic hearing loss category HK2, the two hearing thresholds K2 and L2 diverge in the high frequency range. In the case of the hearing loss category HK3, the two hearing thresholds K3 and L3 run parallel to one another. In the case of another hearing loss category HK4, the two hearing thresholds K4 and L4 are further apart from one another in a medium frequency range and are close together in the high and respectively low frequency range. The database can include numerous further hearing loss categories HKn. In the present case, the spectra of the different categories are characterized in that they exhibit a specific distance pattern in relation to one another.
The measured conduction spectra Km and Lm here run essentially parallel to one another with the exception of one measuring point. A comparison with the database shows that the bone conduction hearing threshold K3 runs parallel to the air conduction hearing threshold L3 in the hearing loss category HK3. The measured hearing thresholds can thus be assigned with high probability to the hearing loss category HK3. The significantly differing measuring point in the measured bone conduction spectrum is thus in all likelihood a mismeasurement. The measured bone conduction hearing threshold Km is thus corrected with the aid of the hearing thresholds K3, L3 of the hearing loss category HK3, so that a corrected bone conduction hearing threshold Kk results. This corrected bone conduction hearing threshold is shown in the center on the left in the FIG. The associated air conduction hearing threshold Lk can remain unchanged and can correspond to the measured air conduction hearing threshold Lm or can also be corrected where necessary.
The target amplification curves Vs for quiet levels, Vm for average levels and Vt for loud levels are created from the corrected conduction hearing thresholds Kk and Lk. A hearing device adjustment using target amplification curves is thus possible, said target amplification curves being based on corrected audiometric data.
With the above-mentioned example only spectra for the bone conduction hearing threshold and the air conduction hearing threshold and/or their differences, the sound conduction components, were recorded in the database for each hearing loss category. Alternatively a database could also be established just with bone conduction hearing thresholds and correction could take place only on the basis of the typical bone conduction hearing threshold patterns. A further alternative consists in the discomfort threshold or another threshold being recorded in addition to the bone conduction hearing threshold or the two hearing thresholds for each hearing loss category. In some circumstances this allows an improved assignment between the measurement curves and the hearing loss categories to be achieved, so that a more reliable correction of mismeasurements can take place.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 020 833.1 | May 2006 | DE | national |
