Abstract: A method and apparatus for conversion between data representation formats and data including sound and text information are disclosed. Data representation formats include a string of characters in the text format, a digital representation of an acoustic wave form in the sound format, a reference to a data structure containing information about a word in the word format, a tree-like representation of the grammatical structure of the phrase in the phrase format and references to functions, objects and attributes in an underlying data model in the logic format. Software for a computer or a combination of hardware and software may be used as well as word and sound processors.

Abstract: Processing for producing encoded output representing information about a pitch period of an input speech signal is performed. The pitch period of a previously entered speech signal is stored in a buffer. A search range-determining portion determines a range in which a current pitch period is analyzed, according to the pitch period of the previously entered speech signal. A presently entered speech signal is applied from a speech input terminal. A pitch analysis portion makes a pitch analysis of candidates for the pitch period contained in the determined search range. Information about the pitch period is delivered from an output terminal and stored in the buffer for subsequent processing. The pitch period of the speech signal can be calculated with a small amount of calculation and represented with a small amount of information.