Past, present, and future applications of the auditory middle latency response

For many years (auditory) middle latency response (MLR) reportedly has been an excellent electrophysiological procedure for estimating frequency specific auditory thresholds. Currently the 40 Hz potential, a derivative of the MLR, holds even greater promise for threshold testing. MLR also appears to have potentially valuable applications in the evaluation of functional hearing loss and assessment of higher auditory function. However, MLR is not without controversy. Questions of origin, filtering effects, and its use in pediatric assessment are current issues surrounding applications of MLR. The following article analyzes the values and limitations of MLR within the framework of past, present, and future research and clinical uses.

Clinical use of primary cortical responses

This paper reviews the use of the primary cortical responses (or middle components of the auditory-evoked potentials) as it has recently developed in the clinical assessment of auditory disorders. Advances in the use of these techniques since 1958 are examined. Recording parameters for the middle components are briefly reviewed. Information is presented on the frequency-specific nature of the response, as well as normative studies with neonates and infants. The clinical application of the middle components is summarized, as well as information about future directions for improving the clinical utility of electroencephalic response recordings.