Middle ear peak sensitivity to frequencies between 1 kHz and 3 kHz. The movement of the ossicles may be stiffened by two muscles. The stapedius muscle, the smallest skeletal muscle in the body, connects to the stapes and is controlled by the facial nerve; the tensor tympani muscle connects to the base of the malleus and is under the control of the medial pterygoid nerve which is a branch of the mandibular nerve of the trigeminal nerve. These muscles contract in response to loud sounds, thereby reducing the transmission of sound to the inner ear. This is called the acoustic reflex. Of
The Life You Can Save book comes from the fact that Singer addresses readers directly, asking them what they will do about "the life "you" can save". Singer says that citizens of richer nations do not donate as much as they could. The author says the reasons are not philosophical, but due to psychological considerations including cognitive dissonance, diffusion of responsibility and the evolutionary history of human ancestors. For instance, according to Singer, cognitive dissonance theory predicts that humans are rationalizing creatures, making it difficult to change their minds on topics (e.g. charity) that cause any anxiety—unless they are highly motivated to bear it during