Comparison of noise-induced changes of auditory brainstem and middle latency response amplitudes in rats

Deterioration of cortical responses to amplitude modulations of low-frequency carriers after high-frequency cochlear lesion in guinea pigs

“…This finding does not agree with the lesion-induced enhancement reported in experiments using surface electrodes (e.g. Popelar et al, 2008). In the present study, a slight increase in response amplitudes to 2 kHz was seen at 40 and 60 dB SPLs, but not at 80 dB SPL three days after the noise exposure ( Figure 3A).…”

“…We did not observe a significant increase in tone-burst evoked response amplitude (shown in Figure 3 as input/output functions) as reported in previous studies (e.g., Wang et al, 2002;Popelar et al, 2008). In the study by Popelar et al, a large increase in the amplitude of the cortical response was recorded after exposure to broadband noise.…”

“…The authors found this effect when using surface electrodes, but stated that they did not observe an enhanced response when using implanted electrodes similar to those employed in the present experiment. They suggested that the disparity might be the result of the difference in spatial selectivity between the two types of electrodes (Popelar et al, 2008). Other possible reasons for the lack of an enhanced response include the restricted area of our cochlear lesion and the different exposure duration used in the present experiment.…”

The possible impact of noise-induced Ca 2+ -dependent activity in the central auditory pathway: A manganese-enhanced MRI study

“…In the present study, only a small, statistically non significant threshold shift could be observed in nearly all tested frequencies. However, hearing loss induced by a second trauma was significant in the 12 kHz range, where the largest effects in threshold shift were found as reported earlier (Popelar et al, 2008).…”

“…An obvious deterioration of ABR thresholds after second noise exposure has already been confirmed in a study by Popelar et al (2008) and might be caused by an additional increase in cellular damage similar to the effects after the first exposure. In the present study, only a small, statistically non significant threshold shift could be observed in nearly all tested frequencies.…”