Send to

Choose Destination
See comment in PubMed Commons below
Ear Hear. 1994 Oct;15(5):390-9.

Three-channel Lissajous' trajectory of human middle latency auditory evoked potentials.

Author information

  • 1Evoked Potentials Laboratory, Technion, Israel Institute of Technology, Haifa.



We provide the normative values for middle latency auditory evoked potentials (MLAEPs) measures (three-channel Lissajous' trajectories or 3-CLT) in response to clicks and tone pips, which are the stimuli most widely used in MLAEP clinical testing. The relationship of 3-CLT measures to the more widely used latency and amplitude characteristics of the single-channel MLAEP of the same subjects was also evaluated. We further relate the 3-CLT findings to the question of MLAEP generators.


3-CLT of MLAEPs were derived from 12 humans (24 ears) in response to 65 dB nHL, rarefaction clicks as well as tone pips (1000 Hz), presented at a rate of 3.3/sec. A normative set of 3-CLT measures was calculated and compared with the corresponding measures of simultaneously recorded, single-channel vertex-left mastoid and vertex-neck derivation of MLAEP.


Apex latencies of 3-CLT were comparable to peak latencies of the vertex-neck record, both in absolute values and in intersubject variability. Durations of planar segments were approximately 5.0 msec. Size and shape measures of planar segments were variable across subjects, making their clinical use, in their present form, questionable.


The results showed two apices and associated planar segments (i1 and i2) in the 3-CLT of MLAEP which corresponded to the vertex-neck component Pa. These results and earlier studies that indicated a dual set of generators for Pa are compatible with a primary auditory cortex generator for i1 and ascending subcortical generators for i2.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Lippincott Williams & Wilkins
    Loading ...
    Support Center