7

88 Chapter 6 Filter
Rate
This knob determines the speed of the modulation. Values to the left of the center
positions are synchronized with the sequencer’s tempo and include bar values, triplet
values and more. Values to the right of the center positions are non-synchronous and
displayed in Hertz (cycles per second).
Note: The ability to use synchronous bar values could be used to perform a formant
shift every four bars on a one bar percussion part, which is being cycled. Alternately,
you could perform the same formant shift on every eighth note triplet within the same
part. Either method can generate interesting results, and can lead to new ideas, or a
new lease of life on old audio material.
U/V Detection
Please refer to “Analyzing Speech Signals”, from page 169 onwards, for an explanation
of the U/V Detection principle.
Speech intelligibility is highly dependent on high frequency content, as human hearing
is reliant on these upper-end frequencies to determine syllables within words. Bear this
fact in mind when using the EVOC 20 TO, and take care with filter frequency settings in
the Synthesis and Formant Filter sections.
To aid intelligibility, it may be worthwhile using equalization to boost particular
frequencies in the mid to high frequency range, before processing the signal with the
EVOC 20 TO. Please see the “Tips for Better Speech Intelligibility” on page 169 for
further information.
Sensitivity
This parameter determines how responsive the U/V detection is. By turning this knob
to the right, more of the individual unvoiced portions of the input signal are
recognized.
When high settings are used, the increased sensitivity to unvoiced signals can lead to
the U/V source—determined by the Mode parameter—being used on the majority of
the input signal, including voiced signals. Sonically, this results in a sound that
resembles a radio signal which is breaking up and contains a lot of static or noise.