Abstract:
Error resilient tools like Packet Loss Concealment (PLC)
and Forward Error Correction (FEC) are essential to maintain a
reliable speech communication for applications like Voice over
Internet Protocol (VoIP), where packets are frequently delayed
and lost. In recent times, end-to-end neural speech codecs have
seen a significant rise, due to their ability to transmit speech signal
at low bitrates but few considerations were made about their
error resilience in a real system. Recently introduced Neural
End-to-End Speech Codec (NESC) can reproduce high quality
natural speech at low bitrates. We extend its robustness to
packet losses by adding a low complexity network to predict
the codebook indices in latent space. Furthermore, we propose
a method to add an in-band FEC at an additional bitrate
of 0.8 kbps. Both subjective and objective assessment indicate
the effectiveness of proposed methods, and demonstrate that
coupling PLC and FEC provide significant robustness against
packet losses.
Preprint: submitted to
INTERSPEECH 2024
