Bandwidth extension of low bitrate compressed audio based on statistical conversion

Algorithmic and protocol constraints of most low bitrate compression schemes lead to audio signals of low bandwidth and, inevitably, of low perceptual audio quality. Audio bandwidth extension methods address this problem by reconstructing the high frequency spectrum of a degraded signal based on information from the low frequency part. In this work, a novel audio bandwidth extension method is presented in which high frequency reconstruction is achieved through statistical conversion between the low frequency spectrum of the compressed signal and the high frequency part of the uncompressed signal´s spectrum. Even though no psychoacoustic model is used, quality evaluation tests show that the proposed method has similar performance to one of the most recent, state-of-the-art, bandwidth extension schemes.