VoATM (Voice over Asynchronous Transfer Mode) is a service used to transport packetized voice signals over an ATM network. The voice traffic is encapsulated using AAL1/AAL2 ATM packets, when sending voice traffic over ATM. VoATM over DSL is a similar service, which is used to carry packetized voice signals over a DSL connection.
VoATM is a multi-service, high speed, scalable technology but rarely found because of its expensive services.
Variable Delay 
Dynamic Bandwidth Circuit Emulation Service (DBCES) does not send a constant bit stream of cells but transmit only at an active voice call, reducing delays and variations.
Echo Cancellation 
See also 
Professional wide band audio over ATM. Audio Engineering Society AES47