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
Silent speech interface by electromyography of speech articulator muscles and the larynx is another technique. Another source of information is the vocal tract resonance signals that get transmitted through bone conduction called non-audible murmurs. They have also been created as a brain–computer interface using brain activity in the motor cortex obtained from intracortical microelectrodes. Such devices are created as aids to those unable to create the sound phonation needed for audible speech such as after laryngectomies. Another use is for communication when speech is masked by background noise or distorted by self-contained breathing apparatus. A further practical use is where a need exists