Do Babies Prefer Speaking or Singing?
Psychologists in Montreal and Toronto conducted a study to determine if babies show any preference for speech over general noise. As part of the same study, the researchers also were interested in whether babies preferred singing or speech. Fifty infants between the ages of 4-13 months were exposed to both happy-sounding infant speech and a hummed lullaby by the same woman. Interest in each sound was measured by the amount of time the baby looked at the woman while she made noise. Forty-eight of the original fifty infants were exposed to both singing and speech by the same woman. Interest was again measured by the amount of time the baby looked at the woman while she made noise. In this case the mean time while speaking was 66.97 with a standard deviation of 43.42, and the mean for singing was 56.58 with a standard deviation of 31.57 seconds. The mean of the differences was 10.39 more seconds for the speaking treatment with a standard deviation of 55.37 seconds. Perform the appropriate test to determine if this is sufficient evidence to conclude that babies have a preference (either way) between speaking and singing.
$^{1}$Corbeil, M., Trehub, S.E., Peretz, I., "Speech vs. singing: infants choose happier sounds," Frontiers in Psychology, 25 June, 2013.
State the null and alternative hypotheses.
Use $\mu_{d}$ for $\mu$ in the response area.
$H_{0}:$
vs $H_{a}:$
