Simplified Classroom Audio Guide
Improving the volume,
clarity, and dispersion of a teacher’s voice makes sense!
If a child can hear the teacher clearly, it is more likely that the child will
understand what the teacher is saying.
We need to capture,
receive, amplify and disperse the teacher’s voice.
Capture: Microphones.
They can be wired or wireless.
Wired headphones limit a teacher's movement around the classroom.
Handheld microphones are fine for singers, but teachers need their hands. A wireless
microphone is more practical. Wireless units transmit (rf) radio signals or (ir)
infrared signals to a tuned receiver. Wireless microphones can be worn on the
lapel, over the head, as a headset or around the neck as a pendant.
Lapel and headset types need to be connected to a belt pack transmitter, the
pendant type and some athletic headsets are complete microphone and transmitter
units.
Wireless Receiver:
A sensor that converts the microphone signals to an electrical sound wave
signal.
Infrared receivers need a wide field of view and must be centrally mounted,
preferably on a ceiling.
Radio frequency receivers utilize antennae and can be out of sight, mounted directly on
or near the
amplifier. Radio signals penetrate walls and may interfere with other devices that
monitor similar frequencies. This interference is minimized by using high frequency
ranges that are not in wide use.
Amplifier:
Increases the volume of the electrical signal and sends that signal to the
speakers. The strength of an amplifier output is measured in Watts. 30 to 100
Watts is enough power for an average sized classroom.
Amplifiers can be mono or stereo and may have additional audio inputs.
Dispersion: Speakers
The number, size and placement of
speakers are the most critical components of any classroom audio system.
Speakers need to be matched to the amplifier and should be mounted as high as
possible above the floor.
The acoustics of each room is important. Sound reflects off of floors and walls,
the returned sound waves produced can interfere with or feedback into the microphone.
Test different speaker placements for the best results.
Just listen, you'll know.
Minimum: One centrally mounted or two wall or shelf mounted speakers placed on opposite
corners facing the students, or in the rear corners of the room aimed toward the
center of the room.
Better: Four
speakers are better than two. Each setup is different.
BEST! Four
to six, evenly spaced, ceiling mounted speakers. These usually are aimed
straight down, however, some ceiling speakers can be aimed for better coverage.
This setup provides an even dispersion of voice and music at a lower volume. The
room literally fills with sound.
COST!
A small desktop PA or Stereo 2 speaker setup should cost between $100.00 -
$400.00
A fully installed ceiling system, will cost from $2,000 to $4,000 for each room.
A do it yourself setup is under $1000.00.
Assisted Technology: Individual student wireless headsets are available and can
be incorporated into any class environment. They provide amplified audio to
individual students.
