This paper investigates the use of a variable low bit-rate speech transmission method for Asynchronous Transfer Mode (ATM) networks, A modified version of an existing 8kbit/s ACELP speech coder, making it an on-off source controlled variable bit-rate coder, referred to as AV-ACELP, has been adopted for this investigation. A possible adaptation of this coder to ATM is proposed and the effects of cell loss, cell delay and congestion control are examined. This paper discusses a suitable packetization method, ATM adaptation layer function and cell loss recovery scheme. Results obtained from this study are compared with results obtained from a standard 32kbit/s embedded ADPCM coder.