International Journal of Scientific & Engineering Research
In recent telecommunications system uses a limited audio signal bandwidth of 300 to 3400 Hz. In recent times it has been proposed that the mobile phone networks with increased audio signal bandwidth of 50Hz-7 KHz will increase the sound quality of the speech signal. In this paper, a method extending the conventional narrow frequency band speech signals into a wideband speech signals for improved sound quality is proposed. A possible way to achieve an extension is to use an improved speech COder/DECoder (CODEC) such as the Adaptive Multi Rate - Wide Band (AMR-WB). However, using an AMR-WB CODEC requires that both telephones at the ends of the communication link support it.