In this paper, we investigate the performance of ATM services to carry low bit rate voice traffic. We show some limitations of AAL-1(ATM Adaptation Layer 1)when it is used for carrying low bit rate voice, for example, low number of voice channels, under-utilise network resources. In contrast, when assessing the use of AAL-2 for carrying low bit rate voice, AAL2 offers a number of advantages when compared with AAL-1. However, the original AAL2 introduces a large overhead leading to low system throughput even a system is operated efficiently. We have proposed a new AAL2 scheme which has a lower overhead. We have shown that our proposed AAL-2 scheme can improve throughput performance of ATM networks when carry low bit rate voice traffic. Our proposed scheme offers a lower overhead as well as a higher number of voice channels.