...Atkinson traced the number distinct sounds, or phonemes — consonants, vowels and tones — in 504 world languages, finding compelling evidence that they can be traced back to a long-forgotten dialect spoken by our Stone Age ancestors, according to the Daily Mail.

Atkinson also hypothesized that languages with the most sounds would be the oldest, while those spoken by smaller breakaway groups would utilize fewer sounds as variation and complexity diminished.

The study found that some of the click-using languages of Africa have more than 100 phonemes, or sounds, whereas Hawaiian, toward the far end of the human migration route out of Africa, has only 13, the Times reported. English has about 45 phonemes.

The phoneme pattern mirrors the pattern of human genetic diversity as humans spread across the globe from sub-Saharan Africa around 70,000 years ago.
http://ukrbgs.co.uk/all-the-worlds-languages-traced-back-to-single-african-mother-tongue/

That language was located somewhere in Western Africa.