Speech impairment is one of the most intriguing and least understood effects of alcohol on cognitive function, researchers said.
Christopher Olson and colleagues at Oregon Health and Science University studied Zebra finches, a representative songbird species, and a powerful model for the study of mechanisms that underlie vocal learning and production.
"We just showed up in the morning and mixed a little bit of juice with 6 per cent alcohol, and put it in their water bottles and put it in the cages," Olson was quoted as saying by 'metro.Co.Uk'.
While alcohol exposure does not visibly affect general behaviours, willingness or motivation to sing, or variability of vocal output, it has marked effects on acoustic features of learned song, particularly entropy and amplitude.
In other words, the birds became less organised in their sound production, researchers said.
The study is published in PLOS ONE journal.