| This applet demonstrates audio
effects resulting from Audio Filters. It is designed for a
first insight into the perceptual effect of filtering an audio
signal. Besides the different filter functions and their acoustical
effect the applet offers a first insight into the logarithmic behavior
of loudness and frequency resolution of our human acoustical
perception.
The following filter functions can be selected on the lower
right of the graphical user interface
- Low-/High-pass filter (LP/HP) with control parameter
- cut-off frequency fc in Hertz (lower horizontal slider)
- all frequencies above (LP) or below (HP the cut-off
frequency are attenuated according to the shown frequency response
- Low/High-frequency shelving filter (LFS/HFS) with
control parameters
- cut-off frequency fc in Hertz (lower horizontal slider)
- boost/cut in dB (left vertical slider with + for boost
or - for cut)
- all frequencies below (LFS) or above (HFS) the cut-off
frequency are boosted/cut according to the selected boost/cut
- Peak filter with control parameters
- center frequency fc in Hertz (lower horizontal slider)
- boost/cut in dB (left vertical slider with + for boost
or - for cut)
- Q-factor Q=fb/fc (right vertical slider), which
controls the bandwidth fb of the boost/cut around the adjusted
center frequency fc. Lower Q-factor means wider bandwidth.
- the peak filter boosts/cuts the center frequency with a
bandwidth adjusted by the Q-factor.
The center window shows the frequency response (filter gain
versus frequency) of the selected filter functions. You can choose
between a linear and a logarithmic frequency axis.
You can choose between two predefined audio files from our
web-server ("audio1.wav" or "audio2.wav") or your own local .wav-file
to be processed.
To run the applet you will need at least a Java VM 1.4 or
later. Please find the latest JRE (Java Runtime Environment) here.
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