He could, but it certainly makes communication harder. I hadn't heard he shot himself in the mouth, but I haven't watched any news all day
they're saying it was a botched suicide attempt
http://www.telegraph.co.uk/news/worldnews/northamerica/usa/10008638/Boston-bomber-FBI-dropped-the-ball-over-Tamerlan-Tsarnaev.html" CBS television quoted investigators as saying that Dzhokhar Tsarnaev suffered two serious wounds and had lost a lot of blood. It said investigators had speculated that one wound in the back of his neck could have been a suicide attempt.
"They say it appears from the wound that he might have stuck a gun in his mouth and fired," said the report, which added that Tsarnaev could understand what those around him were saying.
Gov Patrick said he hopes the teenaged suspect survives. "We have a million questions and those questions need to be answered," he added.
The American Civil Liberties Union and a federal public defender raised concerns about investigators' plan to question Dzhokhar Tsarnaev without reading him his rights.
ACLU Executive Director Anthony Romero said a legal emergency exception applies only when there is a continued threat to public safety and is "not an open-ended exception" to the Miranda rule, which guarantees the right to remain silent and the right to an attorney. "