| 摘要 |
PROBLEM TO BE SOLVED: To convert a voice information of a narrow frequency band into a voice information of a wide frequency band with a small-sized, simple and inexpensive circuit constitution. SOLUTION: A harmonic generation circuit 11 compares the voice data supplied from the outside at every one sample, and detects the top peak and the under peak of the voice data based on these comparison outputs, and detects respective patterns of the comparison outputs between continuous top peaks and under peaks. Further, the circuit 11 forms the addition/subtraction data answering to harmonics according to these respective patterns, and supplies the addition/subtraction data to an adder 13 at the timing corresponding to the above respective patterns. The adder 13 addition/subtraction-processes the addition /subtraction data formed by the harmonic generation circuit 11 to the voice data supplied from the outside. Thus, a harmonic component is added to the original voice data with a small-sized, simple and inexpensive circuit constitution of only the addition/subtraction, and the voice data of the wide frequency band can be formed. |
