To reduce the virulence of a virus, achieved by passaging the virus through tissue culture or live animals. The attenuated virus can be used as a vaccine if it infects and immunizes without causing disease.
To reduce the amount, force, or magnitude of a thing. For instance, when we say that the FM Plus feature on the Solaris automatically attenuates the hearing aid or internal microphone by 20 dB whenever a signal is sent from the transmitter, we mean that it automatically makes the sounds coming from the hearing aid microphone softer by 20 dB.
Reduction in power or strength (amplitude) of a transmitted signal as the signal travels along the cable. Attenuation is caused by capacitance, inductance and resistice losses in the cable. Attenuation is a function of frequency. Genrally, the greater the frequency, the more attenuation. Attenuation is also a function of distance. The greater the distance, the more attenuation. Attenuation is expressed as decibels/unit length and expresses a power loss per distance traveled. Also, frequency must be stated otherwise the data is useless. For example, attenuation specs stated as 6.5 db/[email protected] means that the signal has lost 6.5 decibels of power over the 1000 meters of cable it traveled at a frequency of 10MHz. Attenuation is always present on a cable, as i capacitance. To improve error rates and achieve the reliable data transmission, the communications cable should have the lowest practical combination of the two.
To reduce the amplitude of an electrical signal usually by using a volume control, fader or 'pad'. Also to reduce sound levels acoustically through the use of acoustic absorbers, resonators or structural materials.
The ability of a yeast strain to ferment the sugars in a wort or must. Attenuation is more important in brewing, where a blend of complex wort dextrins and sugars must be broken down by the yeast during fermentation. Variations in yeast strain attenuations and brewing conditions will affect the dryness and body of the finished beer. See also, Flocculation.