Training in ABR
Bone conduction corrections for 500 Hz and 1000 Hz ABR in newborns
Description
Summary of: Ferm, I., Lightfoot, G., & Stevens, J. (2014). Provisional stimulus level corrections for low frequency bone-conduction ABR in babies under three months corrected age. International journal of audiology, 53(2), 132–137. https://doi.org/10.3109/14992027.2013.843027
This paper describes how a click stimulus sets up a traveling wave along the basilar membrane, which excites each of the frequency bands in the cochlea, one after another. Due to the lack in synchronization of the excitations, the compound response amplitude is low. A repetitive click-like stimulus can be set up in the frequency domain by adding a high number of cosines, the frequency intervals of which comply with the desired stimulus repetition rate. Straight-forward compensation of the cochlear traveling wave delay is possible with a stimulus of this type. As a result, better synchronization of the neural excitation can be obtained so that higher response amplitudes can be expected. The additional introduction of a frequency offset enables the use of a q-sample test for response detection. The results of investigations carried out on a large group of normal-hearing test subjects (N = 70) have confirmed the higher efficiency of this stimulus design. The new stimuli lead to significantly higher response SNRs and thus higher detection rates and shorter detection times. Using band-limited stimuli designed in the same manner, a ""frequency-specific"" hearing screening seems to be possible.
Related course: ABR Correction Factors
