id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ap-906	Martinez, M. Herrera	Evaluation of Audio Compression Artifacts	2007	5	.pdf	application/pdf	2667	140	53	Coding signals with a strongly aperiodic character, called “attack signals” or “signals with transient behaviour” lead to an artifact known as preecho. Higher levels of signal decomposition, of course, will give more accurate representations of the audio signal, in a similar manner as higher frequency resolution improves the accuracy of the frequency representation of the signal in FFT. DWT, then, has a hierarchical structure in which the higher the level that the decomposition affords, the longer the hierarchical DWT tree.	cache/ap-906.pdf	txt/ap-906.txt