Log area ratios (LAR) can be used to represent reflection coefficients (another form for linear prediction coefficients)[1] for transmission over a channel.[2] While not as efficient as line spectral pairs (LSPs), log area ratios are much simpler to compute. Let be the kth reflection coefficient of a filter, the kth LAR is:[3]
Use of Log Area Ratios have now been mostly replaced by Line Spectral Pairs, but older codecs, such as GSM-FR use LARs.
↑Strube, H. (October 1977). "Synthesis part of a "Log area ratio" vocoder in analog hardware". IEEE Transactions on Acoustics, Speech, and Signal Processing. 25 (5): 387–391. doi:10.1109/TASSP.1977.1162984. ISSN0096-3518.
↑Gutierrez-Osuna, Ricardo. "L7: Linear prediction of speech"(PDF). Introduction to Speech Processing | Ricardo Gutierrez-Osuna | CSE@TAMU. p.24.