Threshold shifts (means + standard error) of groups treated with Ad-eGFP inoculation via cochleostomy (black bars), HA alone on RWM (white bars), and HA-assisted Ad-eGFP inoculation via RWM (gray bars), and measured 2 weeks after inoculation, at 4, 12, and 20 kHz. Ears inoculated with Ad-eGFP via cochleostomy had average threshold shifts greater than 20 dB at each tested frequency, with larger shifts at higher frequencies, and all three averages were significantly greater than zero (p<0.05 after sequential Bonferroni adjustment). Average threshold shifts of ears treated with HA alone or HA with Ad-eGFP were less than 10 dB and were not significantly different from zero. Moreover, the average shifts induced by HA-assisted Ad-eGFP inoculation were not significantly different from those induced by HA alone, even at 4 kHz where the difference between means was somewhat larger (p>0.5). In addition, threshold shifts for HA-assisted Ad-eGFP inoculation via RWM were statistically lower than in animals inoculated with Ad-eGFP via cochleostomy at 12 kHz (p<0.05) and 20 kHz (p<0.01). For all groups, n=5.