Experimental Investigation of Wave File Compression-Decompression Ahmad Sharadqh , Ziad Al-Qadi, Bilal Zahran, Jihad Nader Department of Computer Engineering Faculty of Engineering Technology Al-Balqaa Applied University, Jordan natalia_maw@yahoo.com Abstract- Wave (audio) files are widely used over the internet and they are typically so large in size, so it is difficult to send them via email. Therefore, we need to reduce WAV file size. This paper aims to provide a method to easily compress WAV files and reconstruct it with minimum loss of information. In this paper an algorithm of compression-decompression wave file based on describe cosine transformed was proposed, tested and investigated. The efficiency of this algorithm is increased through controlling the algorithm parameters such as window size and number of components (coefficients) in each window. The output parameters such as compression ratio, error, compression and decompression times is achieved by selecting a probable values for the input parameters. Keywords: DCT, quantization, encoding, input parameters, output parameters. efficiency. I. INTRODUCTION Wave (audio) files are now the most popular type of digital data used over the internet, and compared to most digital data types, the data rates associated with uncompressed digital audio are substantial. Compression can be considered as a key which reduces the amount of data used to convey the same information [5], [6]. The most popular audio coders are based on using two techniques (i.e., sub-band coding and transform coding). Sub-band coding splits signal into a number of sub-bands, using band-pass filter [7]. Speech Compression is a method to convert human speech into an encoded form in such a way that it can later be decoded to get back the original signal. Compression is basically to remove redundancy between neighboring samples and between adjacent cycles. Major objective of speech compression is to represent signal with lesser number of bits. The reduction of data should be done in such a way that there is acceptable loss of quality. Speech compression-decompression techniques as described in [8[, [9] and [10] can be achieved applying the steps shown in figure 1 and figure 1. Figure 2. Compression phase Figure 2. Decompression phase A. Discrete Cosine Transform The application of the Discrete Cosine Transform to image data compression is International Journal of Computer Science and Information Security (IJCSIS), Vol. 14, No. 10, October 2016 774 https://sites.google.com/site/ijcsis/ ISSN 1947-5500