New York, Feb 20 (IANS) Unlike other forms of caregiving, mothers singing to their babies is a universal behaviour, and new research shows that the act could be mutually beneficial for both the mother and the child.While the songs provide the babies much-needed sensory stimulation that can focus their attention, the act of singing can help mothers bond with their babies and also fight postpartum depression, the study said.Mothers experience a much-needed distraction from the negative emotions and thoughts associated with depression, while also feeling empowered as a parent.The study, published in the Journal of Music Therapy, also explored the acoustic parameters in the singing voices of mothers with post-partum depression."The extraction and analysis of vocal data revealed that mothers with post-partum depression may lack sensitivity and emotional expression in their singing," said study author Shannon de l'Etoile, Professor of Music Therapy at University of Miami Frost School of Music in the US."Although the infants were still engaged during the interaction, the tempo did not change and was somewhat robotic," de l'Etoile said.But the the lack of sensitivity and emotional expression seemed to matter less to the infants as long as they were listening to their mothers."Mothers around the world sing to their infants in remarkably similar ways, and infants prefer these specialized songs," de l'Etoile said. "The tempo and key certainly don't need to be perfect or professional for mothers and infants to interact through song. In fact, infants may be drawn to the personalised tempo and pitch of their mother, which encourage them to direct their gaze toward and ultimately communicate through this gaze," she added.