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 relationship between sound and noise levels is generally described in terms of a signal-to-noise ratio. With a masking noise level between 35 and 100 dB, the threshold for 100% intelligibility is usually a signal-to-noise ratio of 12 dB. The speech signal ranges from about 200-8000 Hz, while human hearing ranges from about 20-20,000 Hz, so the effects of masking depend on the frequency range of the masking noise.