Co-articulated consonant consonant such as is doubly or secondarily articulated. In some English dialects, for example, is a labialized velar that could be transcribed as , but the Japanese is closer to a true labial-velar, . It is common usage to restrict the letter to the former. The glottis controls phonation, and works simultaneously with many consonants. It is not normally considered an articulator, and an ejective such as , with simultaneous closure of the velum and glottis, is not normally considered to be a co-articulated consonant. Co-articulated consonant Co-articulated consonants or complex consonants are consonants produced with two simultaneous places of
Origin of speech rare. Another objection is that in the view of most scholars, speech as we know it emerged relatively late in human evolution, roughly contemporaneously with the emergence of "Homo sapiens." A development as complex as the reconfiguration of the human vocal tract would have required much more time, implying an early date of origin. This discrepancy in timescales undermines the idea that human vocal flexibility was "initially" driven by selection pressures for speech. At least one orangutan has demonstrated the ability to control the voice box. To lower the larynx is to increase the length of the vocal tract, in