What do we know about interpreting corticals of children who have ANSD?

The research about ANSD and CAEPs is still in its early stages. Anu Sharma has published a paper in the International Journal of Audiology (2011) that showed some interesting results. The paper shows that when there are no CAEPs present at e.g. 75 dB SPL unaided, you will have two possibilities.

  1. severe/profound hearing loss
  2. improper auditory skill development (the paper also shows CAEP presence is correlated with hearing aid fitting age)

In addition it is important to also take into account subject state. Poor state (sleepy or drowsy subject) may affect results, and a retest is recommended (or at least test at different intensities or several speech sounds).

Will the accuracy/validity of HEARLab®/CAEP results be affected by neurological disorders/cerebral palsy/stroke?

The following statements are not backed up by any research:

CP makes it mainly difficult to record a decent EEG due to excess muscular activity and thus should not affect the auditory cortex. Unless a stroke damages the auditory cortex, there shouldn’t be any effect on the CAEPs. If the auditory cortex is wiped out, obviously one won’t expect CAEPs to appear.

There is some research being published very recently indicating that subjects with autism and schizophrenia seem to have CAEPs with increased amplitudes (especially when presenting the stimuli rapidly).

So the bottom line is ‘yes, there might be some effect for patients with strokes and neurological disorders, but we cannot say how much and for which subjects exactly’. These disorders shouldn’t prevent you using HEARLab®. If you find a CAEP it means there is still something registering in the auditory cortex. If you don’t find a response, those disorders definitely need to be taken into account to form the bigger picture.

Where can I purchase the HEARLab® system?

HEARLab® can be purchased directly from NAL within Australia, please contact .