A sound amplifier is a listening device that amplifies any type of sound, from spoken words to musical notes. Depending on what it is intended for, this piece of equipment can be used to enhance sounds for an entire audience of concert goers, or to help just one person hear with more clarity. A sound amplifier is often used by patients who are hard of hearing and is also referred to as a hearing aid. A hearing aid usually enhances hearing so that patients who have hearing loss or are hearing impaired are able to hear everyday sounds. A sound amplifier may also refer to electronic equipment used to enhance music at a concert, broadcast speeches into a microphone at a political rally or sporting event or it can be attached to a home stereo system to allow musical sounds to be amplified for listening pleasure.
When a sound amplifier is used in a hearing aid, it is usually a very small electronic device that is inserted directly into the ear canal and powered by batteries. Sometimes the device sits snugly inside the ear and often goes undetected, while it allows the user to hear normal sounds. Hearing aids come in different styles and sizes and are sometimes kept in place with a behind-the-ear piece, similar to eyeglasses.
Often when the term sound amplifier is used, it is in conjunction with making a speech or musical concert more audible to the naked ear by enhancing or amplifying the sound. This is usually achieved by using a large piece of equipment to direct sounds to an audience in an arena, concert hall or outdoor stage. During musical concerts a sound amplifier is often used for long distance hearing, amplifying sounds in large theaters, auditoriums or even across wide open spaces, such as outdoor musical festivals. Rock musicians plug guitars, violins and pianos into amplifiers to enhance their music, making the music louder and more dramatic, reaching out to even the last row of seats.
Sometimes, sound amplifiers are even used in undercover police work for surveillance. This kind of amplifier may be able to enhance a whisper across the room, so that the person wearing the device can hear what is being said, as if they were within earshot. This type of advanced technology is often used to help monitor criminal activity or arrest criminals and solve crimes.