Answer:
Peter Eimas and his collegues found that even infants could discriminate the difference between the /ba/ and the /pa/ sound.
Step-by-step explanation:
Psychologist Peter Deimas and his colleagues from Brown University in 1971 carried out a study on how newborn children may discriminate phonemes. They used for that purpose children between 1 and 4 months old and tried their capacity to differentiate the /ba/ from the /pa/ sound. To find out if the infants could discriminate one and another, they were hooked up in fakes nipples to measure their sucking rate. The more they were interested the faster they sucked. At first, the newborns were exposed to only one sound say /ba/ implying that their sucking rate would be faster at the beginning but steady over repetitions. When the sound was changed to /pa/, in some cases the sucking rate would increase while in some others it wouldn't. For the infants to notice the difference between the sounds, they must have had a really fine-tuned ear.