A comparison of the ASSR to the ABR, specifically with regard to
the utility of the ASSR for estimation of hearing threshold in infants and
young children have prompted. Various issues associated with the comparison of
the two evoked potentials were considered, including frequency specificity,
response generators, the effects of hearing loss and automatic detection
Two studies were undertaken. The first study compared ASSR test
results in relation to c-ABR with the ASSR is based on an automatic detection
algorithm. And the second study did a direct comparison of ASSR and tb-ABR
threshold estimation techniques using adult listeners with the ASSR is based on
observer inspection of waveforms.
Correlations were determined between ABR threshold with each
audiometric threshold and between ASSR thresholds and audiometric thresholds.
The results showed that both c-ABR and
ASSR have significant correlations with the pure-tone audiogram in infants and
children with various degrees of hearing loss. These data suggest that both
c-ABR and ASSR threshold estimates can be used to predict pure-tone threshold
for infants and children who have hearing thresholds in the normal to
severe-to-profound range. However, the discrepancy between behavioral and
evoked potential threshold was generally smaller for ASSR than for ABR.
Finally, click-evoked ABR thresholds and ASSR thresholds may be used together
for comparison to results from the pure tone audiogram.
tb-evoked ABR and the modulated tone-evoked ASSR thresholds were
similar when both were detected with an automatic detection algorithm and that
threshold estimates varied with frequency, stimulus rate, and detection method.
However, both ASSR and tb-ABR have demonstrated clinical efficacy for
estimating the pure-tone audiogram in infants, children, and adults with
Finally, there are some studies suggested that there are no
significant differences in threshold determination between the two techniques.
However, other studies showed an advantage for ASSR over tb-ABR. That are ASSR
can determine the residual hearing for those with severe-to-profound and
profound hearing losses, whereas tb-ABR tests yield “no response” at
transducer output limits for this severity of hearing loss. Another advantage
for the ASSR is that ASSR can ensure electro-physiologic responses that are
objectively interpreted in a short time (104 sec). In comparison, long time (4
min) were required per each trial when testing with tb-ABR.
First, many studies were compared with the present tow studies and the findings
were in a good agreement. Second, the present two studies compare
between ABR and ASSR with behavioral thresholds test. Whereas previous studies
compare between one electrophysiological test and behavioral thresholds test. Third,
In the first study, all results of the behavioral threshold were reliable.
First, no variations on the selection of the participants in the second
study, as all participants were females with normal hearing and close range of age. Second,
the present studies did not indicate if the results of the electrophysiological
tests were reliable or not. Third, cases
demonstrating profound hearing loss were excluded so, the correlation between electrophysiological test and behavioral thresholds test were not investigated in these cases in the first study.