One of the types of objects in Praat. For tutorial information, see Intro 4. Pitch analysis.
A Pitch object represents periodicity candidates as a function of time. It does not mind whether this periodicity refers to acoustics, perception, or vocal-cord vibration. It is sampled into a number of frames centred around equally spaced times.
Pitch commands
Creation:
Drawing:
Viewing and editing:
Synthesis:
Conversion:
Inside a Pitch object
With Inspect, you will see the following attributes:
-
xmin
-
start time, in seconds.
-
xmax
-
end time, in seconds.
-
nx
-
the number of frames (≥ 1).
-
dx
-
time step = frame length = frame duration, in seconds.
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x1
-
the time associated with the first frame, in seconds. This will usually be in the range [xmin, xmax]. The time associated with the last frame (i.e., x1 + (nx – 1) dx)) will also usually be in that range.
-
ceiling
-
a frequency above which a candidate is considered voiceless.
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framei, i = 1 ... nx
-
the frames (see below).
Attributes of a pitch frame
Each frame contains the following attributes:
-
nCandidates
-
the number of candidates in this frame (at least one: the `unvoiced' candidate).
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candidatej, j = 1 ... nCandidates
-
the information about each candidate (see below).
Attributes of each candidate
Each candidate contains the following attributes:
-
frequency
-
the candidate's frequency in Hz (for a voiced candidate), or 0 (for an unvoiced candidate).
-
strength
-
the degree of periodicity of this candidate (between 0 and 1).
Interpretation
The current pitch contour is determined by the path through all first candidates. If the first candidate of a certain frame has a frequency of 0, or a frequency above ceiling, this frame is considered voiceless.
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© ppgb, December 30, 2010