Some speakers simply don't need a grille, perhaps because they are enclosed in a case ( such as speakers found inside personal computers ) and are not meant to produce high fidelity audio, but only audible tones and noises.
42.
Starting with �p�e in the 1930s ( foil was electrified in 1950s, sabre in 1980s ), side judges were replaced by an electrical scoring apparatus, with an audible tone and a red or green light indicating when a touch landed.
43.
Most phreaking boxes are electronic devices which interface directly with a telephone line and manipulate the line or the greater system in some way through either by generating audible tones that invoke switching functions ( for example, the red box.
44.
Because there are 12 ( or 16 ) tone pairs, and typically four tones were sent in rapid succession ( less than one second ), more events could be triggered than by sub-audible tones ( usually 25 Hz and 35 Hz ).
45.
In addition to the Braille cards and computer keyboard provided on his earlier appearances, an audible tone that was in sync with the game board's lights was added in order to give him an indication of when he could begin buzzing in to respond.
46.
Most of the cassettes accompanying filmstrips from the 1970s and 80s would have one side of the cassette with audible tones for use with older manual projectors, and the other side with the same program audio, but with 50 Hz subaudible tones instead for automatic projectors.
47.
In barely audible tones, a chastened and visibly nervous Sen . Alfonse M . D'Amato delivered a rare apology on the Senate floor Thursday, calling his heavily accented remarks about the Japanese-American judge in the O . J . Simpson case " totally wrong and inappropriate ."
48.
Several methods were employed to generate an audible tone at the receiver : ( 1 ) a chopper, ( 2 ) a variable condensor with rotating plates ( slope demodulation ), ( 3 ) a tikker, ( 4 ) a separate heterodyne, and ( 5 ) the autodyne.
49.
If the signals are close but not exactly on the same frequency the mix will not only include the audio from both carriers but depending on the carrier separation an audible tone ( a beat signal ) may be heard at a frequency equal to the difference in the carrier frequencies involved.
50.
This audio signal allows the pilot to concentrate on the external view instead of having to watch the instruments, thus improving safety and also giving the pilot more opportunity to search for promising looking clouds and other signs of lift . A variometer that produces this type of audible tone is known as an " audio variometer ".
