Late Latency Responses, also known as ALR, are components of the auditory evoked potential response. The LLR response is found between 50 and 250 milliseconds from the time of stimulation, and appear to reflect the response of the auditory cortex. LLR testing can help determine the amount and type of hearing loss at specific frequencies, as well as provide information about the presence of nervous system abnormalities, particularly referring to… Read More »Acquiring Late Latency Responses using SmartEP
The 40 Hz response is an event related evoked potential similar to middle latency responses. It is usually considered to be a steady state response due to its periodic repetition. Although its use is still in question, it has been speculated that the response originates within the polysensory areas of the thalamus and/or in the auditory cortex. This Smart Note describes suggested electrode placement, acquisition parameters, and analysis methods, for… Read More »Acquiring a 40 Hz response using SmartEP
Middle Latency Responses, also known as MLR, AMR or AMLR, are components of the auditory evoked potential response. The MLR response is found between twelve and fifty milliseconds from the time of stimulation, after the ABR; this period reflects the response of the auditory cortex. MLR waveforms can be acquired with the use of click or pure tone stimulation. This Smart Note describes suggested electrode placement, acquisition parameters, and analysis… Read More »Acquiring Middle Latency Responses using SmartEP
Electrocochleography may be used to diagnose some vestibular and auditory conditions, such as Meniere’s disease or perilymphatic fistula. This Smart Note describes the methodology for acquiring ECochG responses, including the different types of electrodes that can be used, suggested acquisition settings, and instructions on obtaining the SP/AP ratio as well as the area ratio. ECochG can be acquired by using the Duet and USB platforms. The USBLite and Solo platforms… Read More »Acquiring Electrocochleography responses using SmartEP
When stimulating one ear for the acquisition of evoked potentials, it is possible that the response from the non-test ear may be inadvertently considered to be the response from the test ear. The effects and contribution of the non-test ear response will depend on the level of stimulation it receives. White noise may be delivered to the non-test ear to eliminate, or mask, any possible contributions from the non-test ear… Read More »Evoked potential masking in SmartEP
Bone Conduction testing can help determine the amount and type of hearing loss at specific frequencies, (i.e. hearing threshold), and the presence of any air-bone gap. ABR Bone Conduction testing can provide information about existing conductive hearing problems in the ear canal or middle ear. This Smart Note outlines some suggestions for the use of SmartEP to acquire bone conduction ABR in the Duet, USB, and USBLite platforms.
The HL or Hearing Level scale can be used to easily compare the hearing level differences between test subjects in the same population category. In human populations, this corrected scale is usually determined by the acquisition of behavioral thresholds. However, in cases where the population being tested cannot interactively provide threshold information, it may be necessary to find the normal expected ABR hearing threshold using electrophysiological responses. This Smart Note… Read More »Estimating electrophysiological threshold using SmartEP
Learn the how to use the IHS chirp stimuli in SmartEP and SmartEP-ASSR software. This Smart Note includes suggested acquisition settings for the acquisition of both ABR and ASSR waveforms. This guidance applies for the Duet, USB, USBLite, and Solo hardware platforms.
Learn the process of using the SmartEP software for the acquisition of click evoked ABR waveforms. This Smart Note includes information about electrode placement, acquisition parameters, and peak markings. This guidance applies for the Duet, USB, USBLite, and Solo hardware platforms.
The following Smart Note covers some suggestions for electrode montages when using the 2 channel optical amplifier for the Universal Smart Box platform. Includes descriptions and images of usual electrode placements for use while acquiring auditory evoked responses such as ECochG and ABR.