Mothers across languages change the timbre of their voice in similar ways when they speak to babies, Princeton university neuroscientists report today in the journal Current Biology. This finding will help researchers understand what kind of speech keeps a baby’s attention, which could improve how we teach children.
Timbre is the flavor of music and speech. It’s not a distinct pitch or loudness, but rather the unique collection of frequencies produced by a person or instrument. Timbre is what makes sound distinct: It’s why you can tell a violin from a guitar even if they are playing the same note, or Bob Dylan from Jimi Hendrix even if they are both singing “All Along the Watchtower.”
Timbre is tied to the physical structure of the object producing the sound. Certain tones resonate more fully on a violin than on a guitar, and that resonance allows overtones to color the sound in different ways. You can see the different resonances due to the shape of objects in this video of a classic experiment called a Chladni plate (Mind your ears!):
Each person’s voice box is also an instrument with a unique timbre, though it is malleable and can shift slightly. To imitate the distinct, nasally voice of Donald Duck, says lead author Dr. Elise Piazza, “I might draw back my lips and tighten the back of my throat to create a different tone color.”
It is known that mothers in many languages raise their pitch, slow down their speech and repeat phrases more often when they are trying to attract a baby’s attention. This is known as infant-directed speech, and Piazza and her colleagues wondered if it might cause shifts in timbre as well.
To test this, the team collected snippets of adult-directed and infant-directed speech from 24 mothers as they either talked to …read more
Source:: PBS NewsHour – Science