[The use of long pure-tone stimuli with relatively long-rise-times in clinical electro-cochleography (author's transl)].

The clinical use of the action potentials (SAP) of the acoustic nerve stimulated by sinustone bursts of relatively fast rise times has been described extensively elsewhere. The use of sinus tone bursts with relatively long rise times has the advantage of high frequency specifity. Thresholds for frequences of 500 Hz upwards may be found within a +/-12.5 dB SL confidence intervall. Judging the relation between the N1 amplitude in muV and the stimulus level in dBHL - the socalled Input/Output (I/O) curve - a differentiation between recruiting and non recruiting receptor behaviour can be made. The amplitude latency behaviour of the SAP gives additional information on the acoustic nerve's fibres in the high frequency range. The described method seems expecially useful to determine the Corti' organ's state in problematic cases of hearing defects in children.