A system for identifying a periodicity-related attribute in a multi-frequency signal. The system is configured to produce phase and delay modulated signals from a complex input signal. The system is designed to combine these phase and delay modulated signals to identify a periodicity-related attribute associated with the multi-frequency signal. The system is configured to produce a physically perceptible output based on the identified periodicity-related attribute.

A system for identifying a periodicity-related attribute in a multi-frequency signal. The system is configured to produce phase and delay modulated signals from a complex input signal. The system is designed to combine these phase and delay modulated signals to identify a periodicity-related attribute associated with the multi-frequency signal. The system is configured to produce a physically perceptible output based on the identified periodicity-related attribute.

A system for identifying a periodicity-related attribute in a multi-frequency signal. The system is configured to produce phase and delay modulated signals from a complex input signal. The system is designed to combine these phase and delay modulated signals to identify a periodicity-related attribute associated with the multi-frequency signal. The system is configured to produce a physically perceptible output based on the identified periodicity-related attribute.

Provided are methods and systems for concealing missing segments and/or discontinuities in an audio signal, thereby restoring the continuity of the signal. The methods and systems are designed for and targeted at audio signals, are based on interpolation and extrapolation operations for sinusoids, and do not rely on the assumption that the sinusoids are harmonic. The methods and systems are improvements over existing audio concealment approaches in that, among other advantages, the methods and systems facilitate asynchronous interpolation, use an interpolation procedure that corresponds to time-domain waveform interpolation if the signal is harmonic, and have a peak selection procedure that is effective for audio signals.

A system for identifying a periodicity-related attribute in a multi-frequency signal. The system is configured to produce phase and delay modulated signals from a complex input signal. The system is designed to combine these phase and delay modulated signals to identify a periodicity-related attribute associated with the multi-frequency signal. The system is configured to produce a physically perceptible output based on the identified periodicity-related attribute.

In order to play waveform data back at a variable performance tempo by using waveform data which complies with a desired reference tempo, the present invention performs a timeline-expansion/contraction control on the waveform data to be played back, according to the relationship between the performance tempo and the reference tempo. The present invention also determines whether to limit the playback of the waveform data according to the relationship between the performance tempo and the reference tempo. In the case that playback is to be limited, the present invention stops playback of the waveform data, or reduces the resolution of playback processing and continues playback of the waveform data. The present invention stops playback of the waveform data when, for example, the relationship between the performance tempo and the reference tempo is a relationship in which the waveform data would be played back at a performance tempo which would cause a processing delay or a deterioration of sound quality. As a result, it is possible to preemptively prevent a system freeze and solve problems such as the generation of music which has a slower tempo than the desired performance tempo, or the generation of music which includes the intermittent cutting out of sound due to noise, or a significant reduction to sound quality.

An analog signal generation apparatus includes: a converter which converts an input waveform signal into a one-bit signal; a control section which, in response to a mute-off instruction, controls a pulse width time length of the one-bit signal, output from the converter, to progressively increase from zero to a target value; and a filter which converts the one-bit signal, controlled by the control section, into an analog signal. The control section may further perform, in response to a mute-on instruction, control for progressively decreasing the pulse width time length of the one-bit signal, output from the converter, from a current value to zero. The mute-off instruction is given in response to turning-on of a power supply, and the mute-on instruction is given in response to a power supply OFF instruction.

A music synthesizer is provided. The synthesizer divides an input sound into a plurality of musical bands, and, for each divided band, generates a waveform having a predetermined shape with a period corresponding to a detected pitch and with a level corresponding to a detected level. The synthesizer then adds up the waveforms generated for each band and outputs a result thereof.

An accompaniment data generating apparatus has a storing portion 15 for storing sets of phrase waveform data each related to a chord identified on the basis of a combination of chord type and chord root, and a CPU 9. The CPU 9 carries out a chord information obtaining process for obtaining chord information by which a chord type and a chord root are identified, and a chord note waveform data generating process for generating phrase waveform data indicative of chord notes of the chord root and the chord type identified by the obtained chord information in accordance with the obtained chord information by use of the sets of phrase waveform data stored in the storing portion 15, and outputting the generated data as accompaniment data.