VIDEO: Babies prefer listening to other children than their mum and dad
Cooing mums and dads may be disappointed to hear that babies respond much more fondly to the voices of other infants.
Researchers say the sounds - which five-month-olds preferred 40 per cent more to those of adults - could even prompt better language development and positive emotions in tots.
In a series of experiments, researchers in Canada studied how babies develop their understanding of spoken language.
They found that at even at the pre-babbling stage - before they can form sounds resembling syllables such as "ba ba ba" - babies recognise vowel-like sounds, but they tend to dwell on these sounds when from the mouths of other babes.
The work, a collaboration between Professor Linda Polka, of McGill University, PhD student Matthew Masapollo and linguistics Professor Lucie Ménard, tested how babies respond to vowel sounds by different talkers.
Babies could choose to mute sounds with a button, and ended up listening to infant voices 40 per cent longer than adults.
They found even mum's best imitation of babies' high pitched vowel sounds could not compete with other infants.
Prof Polka said: "Access to infant speech, likely including a baby's own vocalisations, seems to have a broad and significant impact, influencing receptive, expressive and motivational aspects of speech development."
That doesn't mean parents should give up oohing and ahhing in high voices.
But Prof Polka said infants' voices may motivate babies to be more chatty "perhaps energising and supporting spoken language development".
She was due to present the findings at the annual Meeting of the Acoustical Society of America in Minneapolis.