SPEEX

Supports almost all industry standard codec types - G.711 (mu-Law and A-Law), G.722, G.729, G.726, GSM, AMR, EVRC, SMV, iLBC, SPEEX, and more.

- Supports G.711[micro]/a, G.722 (HD-audio), G.726-32, GSM, iLBC, Opus (HD-audio), and Speex codecs

Kanthamanon, Perceptual evaluation of speech quality measurement on speex codec VoIP with tonal language Thai", in Advances in Information Technology, Springer Berlin Heidelberg, 2012, pp.

present a TDMA- (time division multiple access-) based MAC protocol LiT [10] and implement the MAC on an 802.15.4 platform Tmote; the evaluation of LiT shows quick flow setup, low packet delay, and essentiality for real-time applications; however, the speech coder chosen is G.723.1, and the coding bit is 6.3 kbps, but the speech codec power consumption is not considered; in 2012, a Lo3 system based on LiT was reported [15], and it showed that such system bodes well with cost and power constraints in rural regions; the audio codec is SPEEX [16] with data rate of 5.9 Kbps, and the expected lifetime is 5 days.