A user equipment device (UE) comprises physical layer circuitry configured to transmit and receive radio frequency electrical signals with one or more nodes of a radio access network, an audio subsystem configured to generate frames of audio data, and processing circuitry. The processing circuitry is configured to calculate a time delay from generation of an audio data frame by the audio subsystem of the UE device to transmission of an audio data packet by the physical layer circuitry during a voice call, and decrease the time delay to a delay value that preserves a specified minimum time for delivery of the generated audio data frame to the physical layer circuitry to meet a scheduled transmission time of the audio data packet.