An efficient method for formant to reflection coefficient conversion

The exact transformation from formant frequencies and bandwidths to reflection coefficients is a complex and time consuming process. A simple approximate transformation may be performed using a table look-up procedure with linear interpolation. Experiments have been conducted using a four formant model, each formant being represented by a complex conjugate pole pair. The formant bandwidths and the frequency of the fourth formant are assigned constant values. Informal listening has shown that a table with as few as 126 16-bit entries is sufficient to perform this transformation without significant degradation of speech quality.