SIGNAL ENCODING DEVICE AND METHOD, AND SIGNAL DECODING DEVICE AND METHOD

摘要

In a signal encoding device (1), a frequency normalizing section (11) normalizes each spectrum of a spectrum signal by using a normalization factor and sends the normalization factor index of each spectrum to a quantization accuracy determining section (13). The quantization accuracy determining section (13) adds a weight coefficient using the auditory characteristic to the normalization factor index of each spectrum of a normalized range-converted spectrum signal subjected to a predetermined range conversion and determines the quantization accuracy according to the result of the addition. A quantizing section (14) performs quantization with a quantization accuracy corresponding to the quantization accuracy index sent from the quantization accuracy determining section (13). An encoding/code sequence creating section (15) encodes the weight coefficient sent from the quantization accuracy determining section(13) together with the quantization factor index and the quantized spectrum signal.