Auditory evoked responses to pure‐tone stimuli were examined in guinea pigs, with chronically implanted electrodes on the dura mater, by means of the summing computer technique. Two distinct response patterns differing in waveshape, latency, association with the pinna reflex, habituation, and threshold were noted. The first, called the Preyer reflex evoked response (PRER) because it tended to occur in association with the pinna reflex, was a myogenic response. The second was a neurogenic potential called the evoked cortical response (ECR). The ECR response was resistant to habituation and present at low intensities of approximately the same level as those reported by behavioral investigation. Once PRER habituation had occurred, myogenic contamination was no longer a hazard in dural recordings.