Method and device for analyzing a wave signal and method and apparatus for pitch detection

A method for detecting pitch in a sound signal, comprising:

• a wave-trigon transformation (WTT) step for performing wave-trigon transformation on the sound signal;
• an energy-width spectrum calculating step for calculating an energy-width spectrum of the sound signal;
• a candidate chained peak determining step for determining a candidate chained peak on the basis of the energy-width spectrum calculated by said energy-width spectrum calculating step;
• and
• a periodicity determining and evaluating step for determining and evaluating the periodicity of the trigons in said candidate chained peak.

An apparatus for detecting pitch in a sound signal, comprising:

• a wave-trigon transformation (WTT) device for performing wave-trigon transformation on the sound signal;
• an energy-width spectrum calculating means for calculating an energy-width spectrum of the sound signal;
• a candidate chained peak determining means for determining a candidate chained peak on the basis of the energy-width spectrum calculated by said energy-width spectrum calculating means;
• and
• a periodicity determining and evaluating means for determining and evaluating the periodicity of the trigons in said candidate chained peak.

A method for detecting a sentence from a sound signal, comprising:

• a pitch-noise detecting step for detecting pitch segments, noise segments, and high-frequency segments contained in the sound signal;
• a segment combining step for combining the pitch segments, noise segments, and high-frequency noise segments into a sequence of word segments and gaps;
• a sentence gap determining step for determining a set of sentence gaps for defining a candidate sentence area between each pair of adjacent sentence gaps;
• a sentence scoring step for calculating a score for each of at least one of the candidate sentence areas;
• and
• a sentence determining step for determining whether each of said at least one of the candidate sentence areas is a sentence in accordance with the result of the sentence scoring step.

An apparatus for detecting a sentence from a sound signal, comprising:

• a pitch-noise detecting device for detecting pitch segments, noise segments, and high-frequency segments contained in the sound signal;
• a segment combining means for combining the pitch segments, noise segments, and high-frequency noise segments into a sequence of word segments and gaps;
• a sentence gap determining means for determining a set of sentence gaps for defining a candidate sentence area between each pair of adjacent sentence gaps;
• a sentence scoring means for calculating a score for each of the candidate sentence areas;
• and
• a sentence determining means for determining whether each of the candidate sentence areas is a sentence in accordance with the result of the sentence scoring means.