Observing frequency following response in recording of 500 Hz tone burst-evoked auditory brainstem response

Frequency following response (FFR) is a neural response with multiple origins. The purpose of current study is to record FFR with alternative and single polarity 500 Hz tone burst stimuli in the setting of auditory brainstem response (ABR).
The population of this observational study consists of 21 adults (n=42 ears) with a mean age of 22.43 (SD=1.51), with 8 out 21 (38%) being female. The participant shows normal results in otoscopy, tympanometry, acoustic reflex, pure tone audiometry, speech recognition threshold, and speech discrimination score. They underwent ABR with a click and various polarities of 500 Hz tone burst stimuli.
First, latencies of ABR waveform with the alternative polarity of click and tone burst were compared and then with changing the polarity to single polarity, FFR was recorded in 24 ears (about 57%) using the 500 Hz tone burst stimuli. The results showed that in some patients changing the polarity caused a better morphology.
In some cases, FFR can be recorded in ABR setting. In addition, because of large amplitude, they fade away ABR waveforms.