Patent ID: 8013231
Filing Date: 2011-09-06
Classification: G10H,G10L

Abstract:
1. A sound signal expression mode determining apparatus comprising: a sound signal input device that inputs a sound signal produced by performance or singing of musical tones; a characteristic parameter detecting device that divides the input sound signal into frames of predetermined time periods and detects characteristic parameters of the input sound signal with respect to each frame; a reference data storing device that stores reference data in which a plurality of pieces of musical tone information, including a timing of starting and ending each of musical tones of a musical composition, are arranged in time series order; a state transition model generating device that generates a state transition model with respect to each of the musical tones of the plurality of pieces of musical tone information in the reference data; and a sound signal expression mode determining device that carries out a sound signal expression mode determining process in which i) a plurality of expression modes of a performance or song are modeled as respective states, ii) a probability that a section including a frame or a plurality of continuous frames lies in a specific state is calculated with respect to a predetermined observed section based on the characteristic parameters of the frames, and iii) a transition route for which the probability is the greatest is retrieved from among transition routes of the respective modeled states in the predetermined observed section based on the calculated probabilities, thereafter based on which transition route iv) expression modes of the sound signal are determined as being one of the states of silence, attack, sustain, vibrato or release, and v) the respective sections for which the expression modes of the sound signal are to be determined are identified based on transition points of the respective modeled states in the retrieved transition route, wherein the retrieved transition route indicates how the states of the expression modes change in each of the musical tones over time.