It wouldn't be manslaughter. Manslaughter is defined as doing an illegal act that accidentally results in death. Voluntary manslaughter is when you illegally attempt to hurt someone, by they die accidentally. For example, you shove someone out of your way, but they fall and hit their head and die. Involuntary manslaughter is when you do an illegal act that does not intended to harm, but it does. If you tamper with a gas pump at the to steal gas, but it blows up and kills someone, that is involuntary manslaughter.

Making someone laugh is not an illegal act. If there is enough evidence to prove intent, the charge would have to be murder because manslaughter does not apply.