[Notched-noise-BERA: methods and diagnostic use].
BACKGROUND
As Picton demonstrated with case reports in 1978, thresholds of click-evoked potentials do not match to pure tone thresholds if hearing loss differs across the test frequencies. Thus, he developed a stimulation with brief tone pips masked by a notched noise that over the years became the standard method for frequency specific threshold estimation. Currently, new technologies like auditory steady-state responses and Chirp-evoked potentials promise to overcome some disadvantages of the NN-BERA.


METHODS
Thus, a systematic review about the NN-BERA was needed to further compare the competitive technologies. Literature research was performed according to the present guidelines for evidence based medicine. It was found that a meta-analysis with data pooling was impossible because of massive discrepancies of methods and subjects across the retrieved publications.


RESULTS
The differences of means between pure tone thresholds and NN-BERA-thresholds were up to 12 dB. Standard deviations were 2 to 16 dB and generally higher at 0.5 und 1 kHz compared to 2 and 4 kHz. Correlations were r = 0.84 to r = 0.97.


CONCLUSIONS
The NN-BERA faces a growing competition by auditory steady state potentials, chirp-evoked potentials, and distortion product otoacoustic emissions but serves still as the standard for an objective threshold estimation since it's accuracy is well evaluated and the interpretation is independent from statistical tests which accuracy is not sufficiently evaluated at present.
Schönweiler
R
R
Abteilung für Phoniatrie und Pädaudiologie (in der Klinik für HNO-Heilkunde), Universitätsklinikum Schleswig-Holstein, Campus Lübeck. rainer.schoenweiler@phoniatrie.uni-luebeck.de
Raap
M
M
D000328:Adult; D000367:Age Factors; D001299:Audiometry; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D002648:Child; D002675:Child, Preschool; D019317:Evidence-Based Medicine; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006311:Hearing Disorders / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009622:Noise; D017084:Otoacoustic Emissions, Spontaneous; D017410:Practice Guidelines as Topic; D012684:Sensory Thresholds; D013997:Time Factors