Electrical audio signal processing systems and devices – One-way audio signal program distribution – Public address system
Patent
1990-03-21
1992-07-14
Kemeny, Emanuel S.
Electrical audio signal processing systems and devices
One-way audio signal program distribution
Public address system
84605, G10L 702
Patent
active
051310422
ABSTRACT:
A music tone pitch shift apparatus which converts an original audio signal into digital data by way of pulse code modulation (PCM), shifting the pitch, and converting the pitch shifted digital data into an analog signal. The PCM digital data is stored in a ring memory at a given sampling speed, and is read out of the memory by a pair of identical read circuits at a common read addressing speed corresponding to the desired pitch. One of the read circuits starts reading from the opposite address location to the other on the ring memory. Since the read addressing speed is set faster than the write addressing speed when increasing the pitch, and vice versa, overtaking or lapping between the addresses could occur. In switching alternately the read circuits from a now-outputting side to a switching-to side, the read address on the switching-to side circuit is stopped increasing at an address location where a zero-amplitude data has been read, until a zero-amplitude data in phase with that which the switching-to side circuit has read is read by the now-outputting side circuit and the switching is made, immediately before the overtaking or lapping occurs on the now-outputting side circuit. Thus, a smooth connection of the pitch shifted audio signals can be made without including such amplitude modulated components as in the cross fade method, and therefore, a high-quality music tone pitch shift operation can be realized.
REFERENCES:
patent: 4464784 (1984-08-01), Agnello
patent: 4586191 (1986-04-01), Nishimura
patent: 4627090 (1986-12-01), Smith et al.
patent: 4700391 (1987-10-01), Leslie et al.
patent: 4792975 (1988-12-01), Mackay
Kemeny Emanuel S.
Matsushita Electric - Industrial Co., Ltd.
Merecki John A.
LandOfFree
Music tone pitch shift apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Music tone pitch shift apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Music tone pitch shift apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-341999