Hominid hearing & speech

Early humans evolved the anatomy needed to hear each other talk at least 350,000 years ago. This suggests rudimentary form of speech developed early on in our evolution.

The conclusion comes from studies of fossilised skulls discovered in the mountains of Spain. A team of Spanish and US researchers used CT scans to measure the bones and spaces in the outer and middle ears of five specimens, thought to belong to Homo heidelbergensis. This species is thought to be a relative of the ancestral line leading to neanderthals.

The team worked out how well the hearing apparatus they found could respond to sounds of various frequencies.

The hominids' ears would have been sensitive to frequencies between two to four kilohertz, the range most important for understanding human speech. Chimpanzees' ears are relatively insensitive at those frequencies. Their ears are most strongly attuned to sounds peaking at either one kHz or eight kHz.

On the other hand, hearing doesn't always mean listening:

A study of seabirds has confirmed what women have always suspected: men do not listen. Scientists found that female shearwaters judge how much food to bring their chicks from their begging cries. But male shearwaters fetch the same amount of food whether the chicks are crying or not, reports Sky News.

Posted by David on June 22, 2004 8:20 PM