Abstract:
This study investigated the use of the dichotic multiple frequency ASSR technique for characterising normal hearing
in a group of infants. A descriptive research design was implemented to describe ASSR thresholds obtained in 10
normal hearing infant ears (3 male, 2 female participants) between the age of 3 and 8 weeks. Normal hearing was
controlled for by conducting a DPOAE screening test on all ears and ensuring no risk factors for hearing loss were
present. Results indicated mean ASSR thresholds at 0.5, 1, 2, and 4 kHz to vary between 30 and 37 dB, ± 8 - 11 dB
within a range of 20 – 50 dB HL. Eighteen percent of ASSR thresholds were obtained at 20 dB, 45% were obtained
at 30 dB, and 38% were obtained at elevated levels of 40 and 50 dB. The recorded dichotic multiple frequency ASSR
thresholds for infants with normal hearing were within the mild to moderate hearing loss range which makes
differentiating between less severe degrees of hearing loss and normal hearing difficult. Until future research has
been conducted, caution must be practiced when interpreting ASSR thresholds below 60 dB in young infants and
additional techniques such as the ABR must be used to cross-check results.
