Hospital corpsmen were previously trained at Naval Hospital Corps School, Great Lakes, Illinois until the 2011 Base Realignment and Closure Bill caused Hospital Corps School to be relocated to the Medical Education and Training Campus (METC) at Joint Base San Antonio, Texas.
characteristic of highness or lowness of a sound is called The frequency of a sound wave determines the pitch of the sound you hear. Remember that frequency is the number of waves passing a fixed point in a given period of time. A high-frequency wave with short wave-lengths, such as that produced by a tiny flute, makes a high-pitched sound.
The speed varies depending on atmospheric conditions; the most important factor is the temperature. Humidity has little effect on the speed of sound, nor does air pressure by itself. Air pressure has no effect at all in an ideal gas approximation. This is because pressure and density both contribute to sound velocity equally, and in an ideal gas the two effects cancel out, leaving only the effect of temperature. Sound usually travels more slowly with greater altitude, due to reduced temperature.