Method and apparatus for automatic non-cooperative frequency specific assessment of hearing impairment and fitting of hearing aids

• US 7,223,245 B2
• Filed: 01/29/2003
• Issued: 05/29/2007
• Est. Priority Date: 01/30/2002
• Status: Active Grant

• Current Assignee: Natus Medical Incorporated
• Original Assignee: Natus Medical Incorporated
• Inventors: Zoth, Peter, Janssen, Thomas
• Primary Examiner(s): Hindenburg; Max F.
• Application Number:
  US10/353,350
• Publication Number:
  US 20030144603A1
• Time in Patent Office: 1,581 Days
• Field of Search: 600/559, 600/372, 600/379, 600/378, 600/382, 600/383, 600/544, 600/545, 600/547, 735/85, 735/84
• US Class Current: 600/559
• CPC Class Codes: A61B 5/121 evaluating hearing capacity
• CPC Class Codes: G01N 2291/02872 Pressure
• CPC Class Codes: H04R 25/70 Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting

Abstract

A method and device for automatically assessing loss of hearing sensitivity and compression (recruitment) with user defined frequency resolution by means of extrapolated DPOAE I/O functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested using a device having a display screen attached to a handheld device generating and collecting otoacoustic emission signals and brain stem response signals into a programmed with a clinical audiogram with fitting parameters for hearing aids calculated on the basis of assessed hearing threshold and compression and identifying the type of hearing required for the individual.

Claims

1. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids comprising:

means for generating one or more stimuli with acoustic transmitters in each ear canal of a subject,

signal collecting means for collecting any transient evoked and distortion product otoacoustic emissions generated by the cochlea in response to the stimulus with microphone means placed in the ear canal for generating a frequency mixed product electric signal, and/or brain stem responses via scalp attached electrodes,

computer means with computer display for analyzing the response signal distortion product otoacoustic emission input/output functions (DPOAE I/O-functions), which mirror the sensitivity and non-linear compression of cochlear outer hair cells, and/or auditory brainstem responses, especially, high rate click evoked ABRs and amplitude modulated following responses (AMFRs),

means for representing neural sound processing in afferent nerve fibers using binomial statistics, different artifact categories by a digital signal processor associated with the signal collecting means,

means for displaying the signal responses of the subject,

means for employing a hardware interface for hearing instruments (HIPRO box) associated with the signal collecting means allowing the test subject to interact with a computer display of test responses, and calculating hearing aid fitting parameters at selected f2 from DPOAE I/O-functions.

means for fitting a hearing aid to supply frequency specific and input level dependent amplification to provide for a subject'"'"'s needs, and

means for displaying the results.

2. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 1, wherein the otoacoustic emissions cochlea scan testing data and brain stem audiologic testing data is inputted into a computer for further analysis for entry into a HIPRO-box to prescribe the required hearing aid for a patient.

3. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 1, including switching means selectively activating measuring equipment means which perform:

DPOAE Cochlea-Scans,

ABR Cochlea-Scans,

Automatic Non Cooperative (ANC) Hearing Aid Fitting,

Screening,

ABR-Inter Peak Latency assessment, (IPL) and

Typanometry differentiation of middle ear, cochlear, and neural disorders.

4. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 1, wherein results from DPOAE Cochlea-Scan and ABR Cochlea-Scan measurements are displayed on a screen as follows:

In the event of estimated hearing loss being lower than 15 dB for all frequencies, the indicator “

normal hearing”

,

In the event of estimated hearing loss being more than 15 dB HL and lower than 25 dB HL for at least one frequency, the indicator “

slight hearing loss”

,

In the event of estimated hearing loss being more than 25 dB HL and lower than 30 dB HL for at least one frequency, the indicator “

mild hearing loss”

,

In the event of estimated hearing loss being more than 30 dB HL and lower than 50 dB HL for at least one frequency, the indicator “

moderate hearing loss”

, and

In the event of estimated hearing loss being more than 50 dB HL and lower than 70 dB HL for at least one frequency, the indicators “

severe hearing loss”

,

In the event of estimated hearing loss being more than 70 dB HL for at least one frequency, the indicators “

profound hearing loss”

.

5. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 4, wherein for severe hearing losses and higher readings, the switching means activate tympanometry means which perform tympanometry, and display if normal, an indicator that the middle ear is affected.

6. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 5, wherein for severe hearing losses and higher readings wherein the middle ear is affected, the switching means activate measuring equipment which perform an ABR IPL test to determine if the IPL is normal and thereby generates an “

AN not affected display,” and

if not, generates an “

AN affected display.”

7. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested comprising:

means for generating one or more acoustic stimuli in the subject'"'"'s ear canal by means of a sound probe with seal and an acoustic stimuli generator such as one or more loudspeakers,

means for recording any transient (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) generated by the cochlea in the subject'"'"'s ear canal in response to the acoustic stimuli by collector means,

means for inputting the collector mean'"'"'s output-signal into a signal processor,

means for calibrating the acoustic stimuli in the ear canal by checking the sound probe'"'"'s seal and estimating sound pressure proximate the eardrum by generating a defined stimulus level signal in front of the eardrum,

means for analysing amplitude, phase, and frequency of cochlear responses,

means for evaluating the responses and signals by binominal statistics or signal-to-noise estimates to determine whether the measured signals contain stimulus correlated components on a defined level of significance,

means for estimating the cochlear responses at threshold as well as at stimulus levels higher than applied by extrapolating cochlear responses (OAE I/O-functions) that are generated within the dynamic range of the acoustic stimulation,

means for converting the estimated stimulus levels at threshold (dB SPL) into hearing loss levels (dB HL) and reconstructing a clinical audiogram, and

means for estimating cochlear compression from extrapolated OAE I/O-functions for providing the gain of hearing aid needed to provide subject'"'"'s normal hearing.

8. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, including:

means for expanding the assessment of hearing loss and loss of compression by additionally measuring auditory brainstem responses (ABR) to the stimuli,

means for providing objective hearing aid fitting parameters derived from estimated hearing loss and compression, preparing the data using hearing aid specific software, and adjusting the hearing aid via an interface,

means for measuring middle-ear impedance for checking middle ear status,

means for measuring ABR inter-peak-latency for checking eighth-nerve function,

means for performing newborn hearing screening (TEOAE, DPOAE, ABR) providing “

pass/refer”

responses,

means for accelerating measurement by automatically intervening in the measuring process by querying the status of different measuring procedures and values, and

display means for indicating type and degree of hearing loss by displaying respective graphs and comments.

9. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, wherein DPOAE are generated and measured at different stimulus levels within the entire dynamic frequency range of electro-acoustic transducers and at different frequencies, the frequency resolution being equal to or higher than the frequency resolution known from of a clinical audiogram, for obtaining OAE I/O-functions that mirror the non-linear compressive sound processing at different cochlear sites.

10. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein DPOAE I/O-functions are extrapolated for estimating stimulus levels necessary for generating cochlear responses at the subject'"'"'s threshold and at stimulus levels out of an electro-acoustic transducers'"'"' dynamic range.

11. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, wherein TEOAE I/O-functions are recorded and separated in different frequency specific TEOAE-components representing cochlear responses at different sites in the cochlea and plotted in a semi logarithmic plot and curve fitted by linear regression analysis or any other curve fitting procedures using the intersection of the regression line with the stimulus level axis as an estimate for the stimulus level which would generate a TEOAE at the subject'"'"'s hearing threshold.

12. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein

a. DPOAE I/O-functions are elicited using a primary tone level setting that accounts for the different suppression of the two primary tones at the DPOAE generation site of the cochlea plotted in a semi logarithmic plot and

b. fitted by linear regression analysis using the intersection of the regression line with the stimulus level axis as an estimate for the stimulus level to generate a DPOAE at the subject'"'"'s hearing threshold, and wherein the DPOAE sound pressure function is represented as

 

p_DP(L₂)=a (L₂−

b), with a giving the slope and b representing the L₂ threshold value L_EDPT where DPOAE pressure is zero.

13. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 12, wherein DPOAE I/O-functions are fitted by weighted Least Mean Square Extrapolation regression analysis using independent weighting factors.

14. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein DPOAE I/O-functions are fitted by other mathematical methods.

15. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein a correlation coefficient gives a measure of accuracy of the fit for evaluating the accuracy of hearing threshold estimation and can be used as a criterion for repeating or rejecting measurement if it is smaller than a defined value, and user defined slope values such as a negative slope, and/or predetermined minimum values within the I/O-function provide criteria for repeating or rejecting measurements.

16. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9 wherein the estimated stimulus level which would elicit a cochlea response at the hearing threshold is used for estimating hearing loss.

17. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 16, wherein the estimation of hearing loss is performed at selected frequencies providing hearing loss levels in dB HL by converting the estimated stimulus levels from dB SPL to dB HL.

18. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 17, wherein the estimated hearing threshold is plotted in the form of a clinical audiogram.

19. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 18, wherein the estimated hearing threshold is plotted in the form of a clinical audiogram in which hearing loss classes such as normal hearing, slight hearing loss, mild hearing loss, moderate hearing loss, severe hearing loss, and profound hearing loss are indicated for classifying hearing loss at tested frequencies.

20. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 19, wherein the corresponding area of maximum hearing loss is marked and/or high-lighted in a manner to provide comment on the degree of hearing loss in addition to the hearing threshold.

21. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 18, wherein the hearing threshold is extrapolated to higher or lower audiogram frequencies by using estimated hearing threshold values at frequencies between the audiogram frequencies.

22. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein the slope s and/or the compression factor k=1/s of the DPOAE I/O-function at selected f2 frequencies provides the compression profile k(f) for matching hearing aid fitting parameters.

23. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 11, wherein the slope s and/or the compression factor k=1/s of the frequency specific TEOAE I/O-function provides the compression profile k(f) for matching hearing aid fitting parameters.

24. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein high click rate evoked ABRs and/or amplitude modulated following responses (AMFRs) are measured if the calculation of hearing loss and compression loss by means of OAE I/O-functions is incomplete.

25. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 24, wherein high click rate evoked ABRs and/or AMFRs are calculated from the frequency spectrum providing I/O-functions for estimating threshold and compression of cochlear responses.

26. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 25, wherein ABR/AMFRs threshold estimates are used for reconstructing the clinical audiogram especially in that range where OAE threshold estimates are missing.

27. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 25, wherein OAE/ABR/AMFRs threshold and compression estimates are used for calculating hearing aid fitting parameters and adjusting the hearing aid'"'"'s for compensating loss of sensitivity and loss of compression (recruitment) in its different channels.

28. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein hearing threshold level and input-level dependent gain are calculated from extrapolated DPOAE I/O-functions, and hearing aid fitting parameters are calculated and prepared by using hearing aid specific computer software to generate hearing aid fitting parameters also used to adjust the hearing aid.

29. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 28, wherein hearing threshold level and input-level dependent gain are calculated from extrapolated ABR and/or AMFRs I/O-functions, and/or wherein hearing threshold level and input-level dependent gain are calculated from I/O-functions that are reconstructed of a mixture of OAE, ABR, and AMFRs I/O-functions and prepared by using hearing aid specific computer software to generate hearing aid fitting parameters also used to adjust the hearing aid.

30. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, wherein calibration of the sound pressure in the ear canal after inserting the sound probe is automatically performed for checking the sound probe'"'"'s seal and estimating volume and length of the subject'"'"'s ear canal.

31. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, wherein the display means include a screen indicating, after the sound probe'"'"'s seal is checked by analysing the pattern of the frequency response and in the event of insufficient seal where sound pressure at low frequencies is below a distinct value, notifying the tester to replace the sound probe by a graph on the screen.

32. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, wherein sound pressure at the eardrum is calculated for selected frequencies from the estimated individual ear canal length and volume, and estimates of middle ear/inner ear impedance are measured or estimated using mathematical models in order to control the loudspeakers'"'"' voltage for generating defined sound pressure in the front of the eardrum.

33. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 9, wherein additional acoustic stimuli are delivered in the outer ear canal in order to suppress secondary responses generated below and above the cochlea site of the primary response.

34. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 8, including in addition to the recording means of OAE and ABR I/O-functions ABR-Inter-Peak-Latency assessment and tympanometry means for differentiating middle-ear, cochlear, and neural disorders.

35. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 34, including means for determining by pattern recognition ABR inter-peak-latencies (IPLs), and displaying:

If there are normal IPLs an indicator that the auditory nerve not affected,

If the IPLs exceed normal ranges, an alternative indicator that the auditory nerve is affected, and

If no IPL determination is possible, no comment is displayed.

36. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 8, including impedance means to measure electrode impedance, and in the event of sufficient user defined conductivity, measuring is continued automatically, or, if insufficient, directing the tester to check electrodes.

37. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 8, including means of pattern recognition to classify tympanograms and display there status for:

A peaked tympanogram with normal compliance is displayed as normal middle-ear function,

A peaked tympanogram with low compliance is displayed as otosclerosis,

A flat tympanogram with low compliance is displayed as a fluid filled tympanic cavity,

A tympanogram with maximum compliance shifted in the negative pressure range is displayed as Eustachian tube dysfunction.

38. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 8, including means for displaying “

pass/refer”

responses in addition to the recording of OAE and ABR I/O-functions TEOAE, DPOAE, and ABR hearing screening test results.

39. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 7, including employing a switch selector to start alternatively (i) assessment of cochlear sensitivity and compression by means of OAE, (ii) assessment of cochlear sensitivity and compression by means of ABR, (iii) automatic non-cooperative hearing aid fitting according, (iv) new born hearing screening methods with “

pass/refer”

responses, (v) detection of neural disorders, (vi) determination of middle-ear status, and (vi) stop measurement.

40. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 39, wherein the switch select or primary measuring procedures automatically initiates secondary measuring procedures, depending on user defined criteria.

41. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 40, including classifying means to display the results of switch selected primary measuring procedures and secondary measuring procedures by type and degree of hearing loss.

42. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 41, including displaying on the screen the results from DPOAE Cochlea-Scan measurements as follows:

In the event of estimated hearing loss being lower than 15 dB for all frequencies, the indicator “

normal hearing”

,

In the event of estimated hearing loss being more than 15 dB HL and lower than 25 dB HL for at least one frequency, the indicator “

slight hearing loss”

,

In the event of estimated hearing loss being more than 25 dB HL and lower than 30 dB HL for at least one frequency, the indicator “

mild hearing loss”

,

In the event of estimated hearing loss being more than 30 dB HL and lower than 50 dB HL for at least one frequency, the indicator “

moderate hearing loss”

, and

In the event of estimated hearing loss being more than 50 dB HL for at least one frequency, the indicators “

severe hearing loss”

or “

profound hearing loss”

depending on ABR Cochlea Scan.

43. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 42, including means for performing the following switching sequences:

i) in the case of “

normal hearing”

, returning to the “

switch select”

status.

ii) in the case of “

slight hearing loss”

, returning to the “

switch select”

status, or performing a tympanometry measurement,

iii) in the case of “

mild hearing loss” and

“

moderate hearing loss”

, performing a Tympanometry measurement, and

iv) in the case of estimated hearing loss more than 50 dB HL, performing an ABR Cochlea Scan measurement.

44. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 43, including means for initiating a tympanometry measurement when ABR Cochlea-Scan measurement results show a hearing loss lower than 70 dB HL, and returning to “

switch select”

status when the ABR Cochlea-Scan measurement results in a hearing loss higher than 70 dB HL display “

profound hearing loss”

.

45. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 43, including means for displaying when tympanometry measurements reveal middle-ear disorder “

middle ear affected;

or for normal middle ear functions, “

middle ear not affected”

, and performing in both cases an ABR Inter-Peak-Latency measurement, and displaying in the case of normal inter-peak-latency “

Auditory nerve (AN) not affected”

in the case of abnormal inter-peak-latency “

Auditory Nerve affected”

.

46. An apparatus for automatically assessing loss of hearing sensitivity and loss of compression (recruitment) with user defined frequency resolution by means of extrapolated OAE I/O-functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested according to claim 40, wherein during measurement sequence, a “

stop”

switch in the “

switch select”

status displays an inquiry for the tester to return to “

switch select”

status.