Abstract: A sound analysis apparatus stores sound source structure data defining a constraint on one or more of sounds that can be simultaneously generated by a sound source of an input audio signal. A form estimation part selects fundamental frequencies of one or more of sounds likely to be contained in the input audio signal with peaked weights from various fundamental frequencies during sequential updating and optimizing of weights of tone models corresponding to the various fundamental frequencies, so that the sounds of the selected fundamental frequencies satisfy the sound source structure data, and creates form data specifying the selected fundamental frequencies. A previous distribution imparting part imparts a previous distribution to the weights of the tone models corresponding to the various fundamental frequencies so as to emphasize weights corresponding to the fundamental frequencies specified by the form data created by the form estimation part.

Abstract: A similarity assessment apparatus is provided for assessing a performance sound based on a model performance sound. In the apparatus, a probability density function generating unit divides data of a performance sound into a sequence of frames each having a predetermined temporal length, and generates a probability density function of a fundamental frequency for each frame of the performance sound. A probability density function providing portion provides a probability density function of a fundamental frequency for each frame of the model performance sound. A similarity assessment unit compares the generated probability density function of a frame of the performance sound with the provided probability density function of a frame of the model performance sound so as to assess a similarity between the performance sound and the model performance sound.

Abstract: An electronic hi-hat cymbal comprises a hi-hat having a strike detector, a pedal unit having a stepped degree detector, a waveform data memory for storing a plurality of electronic hi-hat sound waveform data, corresponding to respective stepped degrees, in a plurality of stages, a CPU, a musical tone generating controller, and so forth. The CPU causes the musical tone generating controller to read out electronic hi-hat sound waveform data corresponding to a stepped degree in the pedal unit from the waveform data memory when a strike to the hi-hat is detected to thereby generate a musical tone signal before outputting, and when a change occurs to the stepped degree during a musical tone being produced thereafter, to read out electronic hi-hat sound waveform data corresponding to a new stepped degree halfway through to thereby generate a musical tone signal to be outputted, which is continued while the musical tone is being produced.

Abstract: Character value of a sound signal is extracted for each unit portion, and degrees of similarity between the character values of the individual unit portions are calculated and arranged in a matrix configuration. The matrix has arranged in each column the degrees of similarity acquired by comparing, for each of the unit portions, the sound signal and a delayed sound signal obtained by delaying the sound signal by a time difference equal to an integral multiple of a time length of the unit portion, and it has a plurality of the columns in association with different time differences. Repetition probability is calculated for each of the columns corresponding to the different time differences in the matrix. A plurality of peaks in a distribution of the repetition probabilities are identified. The loop region in the sound signal is identified by collating a reference matrix with the degree of similarity matrix.

Abstract: A similarity assessment apparatus is provided for assessing a performance sound based on a model performance sound. In the apparatus, a probability density function generating unit divides data of a performance sound into a sequence of frames each having a predetermined temporal length, and generates a probability density function of a fundamental frequency for each frame of the performance sound. A probability density function providing portion provides a probability density function of a fundamental frequency for each frame of the model performance sound. A similarity assessment unit compares the generated probability density function of a frame of the performance sound with the provided probability density function of a frame of the model performance sound so as to assess a similarity between the performance sound and the model performance sound.

Abstract: Respective waveform data on pad strike sounds, rim strike sounds, and rim-shot sounds are stored in a waveform memory, and when a CPU detects a strike detection signal outputted by either of a pad sensor, and a rim sensor, provided in a head unit, a musical tone generating controller reads out waveform data on an strike sound corresponding to the strike detection signal from the waveform memory, thereby generating a musical tone signal corresponding thereto before outputting. Thereafter, when the CPU detects a strike detection signal outputted by the other of the pad sensor, and the rim sensor within a predetermined time, waveform data on a rim-shot sound are read out from the waveform data memory, thereby generating a musical tone signal corresponding thereto before outputting. A sound output unit produces electronic strike sounds corresponding to those musical tone signals, respectively.

Abstract: In a pitch estimation apparatus, a function estimation part estimates a fundamental frequency probability density function of an audio signal by repeating a weight calculation process and an estimated shape specification process. The weight calculation process calculates a weight of each tone model of each fundamental frequency based on an estimated shape of each tone model of each fundamental frequency. The estimated shape indicates a degree of dominancy of a corresponding tone model in a total harmonic structure of the audio signal. The estimated shape specification process specifies each estimated shape of each tone model based on an amplitude spectrum of the audio signal, the harmonic structure of each tone model and the weight of each tone model. A similarity analysis part calculates a similarity index value indicating a degree of similarity between each tone model and corresponding estimated shape.

Abstract: A sound analysis apparatus employs tone models which are associated with various fundamental frequencies and each of which simulates a harmonic structure of a performance sound generated by a musical instrument, then defines a weighted mixture of the tone models to simulate frequency components of the performance sound, further sequentially updates and optimizes weight values of the respective tone models so that a frequency distribution of the weighted mixture of the tone models corresponds to a distribution of the frequency components of the performance sound, and estimates the fundamental frequency of the performance sound based on the optimized weight values.

Abstract: An electronic percussion instrument which is capable of accurately discriminating roll performance to thereby electronically produce percussion tones closer to tones produced by a natural percussion instrument. A waveform memory 6 stores waveform data of percussion tones to be output for roll performance and waveform data of percussion tones to be output for non-roll performance. A work memory 4 stores values of parameters. A drum pad 1 has a percussion surface part 10, and a percussion pattern-detecting section detects a pattern of percussion applied to the percussion surface part 10 of the drum pad 1 and outputs a value of the parameter indicative of the detected pattern of percussion. The values of the parameter output from the percussion pattern-detecting section are sequentially stored in a buffer area of the work memory 4 in the order of output.

Abstract: A sound analysis apparatus stores sound source structure data defining a constraint on one or more of sounds that can be simultaneously generated by a sound source of an input audio signal. A form estimation part selects fundamental frequencies of one or more of sounds likely to be contained in the input audio signal with peaked weights from various fundamental frequencies during sequential updating and optimizing of weights of tone models corresponding to the various fundamental frequencies, so that the sounds of the selected fundamental frequencies satisfy the sound source structure data, and creates form data specifying the selected fundamental frequencies. A previous distribution imparting part imparts a previous distribution to the weights of the tone models corresponding to the various fundamental frequencies so as to emphasize weights corresponding to the fundamental frequencies specified by the form data created by the form estimation part.

Abstract: An electronic percussion instrument which is capable of accurately discriminating roll performance to thereby electronically produce percussion tones closer to tones produced by a natural percussion instrument. A waveform memory 6 stores waveform data of percussion tones to be output for roll performance and waveform data of percussion tones to be output for non-roll performance. A work memory 4 stores values of parameters. A drum pad 1 has a percussion surface part 10, and a percussion pattern-detecting section detects a pattern of percussion applied to the percussion surface part 10 of the drum pad 1 and outputs a value of the parameter indicative of the detected pattern of percussion. The values of the parameter output from the percussion pattern-detecting section are sequentially stored in a buffer area of the work memory 4 in the order of output.

Abstract: Respective waveform data on pad strike sounds, rim strike sounds, and rim-shot sounds are stored in a waveform memory, and when a CPU detects a strike detection signal outputted by either of a pad sensor, and a rim sensor, provided in a head unit, a musical tone generating controller reads out waveform data on an strike sound corresponding to the strike detection signal from the waveform memory, thereby generating a musical tone signal corresponding thereto before outputting. Thereafter, when the CPU detects a strike detection signal outputted by the other of the pad sensor, and the rim sensor within a predetermined time, waveform data on a rim-shot sound are read out from the waveform data memory, thereby generating a musical tone signal corresponding thereto before outputting. A sound output unit produces electronic strike sounds corresponding to those musical tone signals, respectively.

Abstract: An electronic hi-hat cymbal comprises a hi-hat having a strike detector, a pedal unit having a stepped degree detector, a waveform data memory for storing a plurality of electronic hi-hat sound waveform data, corresponding to respective stepped degrees, in a plurality of stages, a CPU, a musical tone generating controller, and so forth.