Abstract: A compressing method for digital audio files mainly utilizes a harmonic structure quad tree (HSQT) to re-arrange the frequency coefficient in each frame, and applies concurrent encoding in hierarchical trees (CEIHT) algorithm to increase and simplify the processing speed; the coefficient of the CEIHT is symbolized according to an arithmetic coding; the record of the probability of the symbol is used to determine the number of bits to be stored; the probability is in inverse order of the number of bits requiring storage, and thus increasing the occurrence probability of the symbol may greatly reduce the number of bits to be stored. As a result, the overall compressing method is done in simplified processing procedures and outputting an audio compressed file with a high compression ratio.

Abstract: A method for translating two-dimensional data of a DWT system has a stairway scan way with a border extension to translate a two-dimensional data to at least two one-dimensional data to be able to execute in the Wavelet transform. The one-dimensional data with less extension data in executing the wavelet transform not only uses small size memory but also has high transforming speed. Therefore the two-dimensional data is compressed by the wavelet transform with the boundary extension process according to the present invention has good compressed rate.

Abstract: A “virtual string” is generated for synthesizing sound produced by plucked-string instruments using recurrent neural networks. The disclosed recurrent neural network, called a Scattering Recurrent Network (SRN), is based on the physics of waves traveling in the string. Vibration measured from a plucked string is used as the training data for the SRN. The trained SRN is a virtual model capable of generating tones similar to the tones generated by the physical string. As with a real string, the “virtual string” corresponding to the SRN responds differently to different types of string “plucking” motions.

Abstract: A music accompaniment machine processes a music accompaniment file to alter a stored beat of the music accompaniment file to match a beat established by a user. The machine identifies the beat of the user using a voice analyzer. The voice analyzer isolates the user's singing signal from excess background noise and appends segment position information to the singing signal, which is indicative of the beat established by the singer. A MIDI controller alters the musical beat of the music accompaniment file so that it matches the beat established by the user.

Abstract: A real time dynamic MIDI controller pre-processes MIDI files to facilitate playback by re-formatting stored MIDI files into a modified MIDI file format and simultaneously eliminating MIDI META events that are stored in the file, but unnecessary for playback. The MIDI controller includes an administrator to effect channel grouping, channel voice message grouping, or a combination thereof, to facilitate the control of selected MIDI file parameters. The real time dynamic MIDI controller also includes an output interface circuit to coordinate the transmission of one or more MIDI file that the MIDI controller has processed.

Abstract: A reverberation network for processing an audio signal including a plurality of wave-ladder filters, each of which simulates a corresponding reflected audio signal from wave propagation in a selected direction, wherein each of the plurality of wave-ladder filters receives as input a signal derived from the audio signal; and an adder which combines the corresponding reflected signals of the plurality of wave-ladder filters to produce a reverberation signal.