Thank you for visiting our website. Please take note of the important information below:

The information on this site regarding the TWELP vocoder pertains to the previous version (4.x.x).

Currently, this vocoder (version 5.x.x) has been significantly improved in speech quality for all bit rates.

The most substantial improvements are seen in bit rates below 2400 bps.
Additionally, new scalable modes of 1200/2400 bps and 700/1600 bps are now available.

All TWELP vocoder pages will be progressively updated in the near future.
We will provide updates on each change on our News page. 

 

Ideal interoperable HF/VHF/UHF Digital Voice 

TWELP 1200/2400 bps Scalable Vocoder ensures the highest voice quality both in HF and in VHF/UHF networks and maintains lossless interoperability between them.
Transcoding is not needed, which saves significant computational resources in gateways and also means no degradation in speech quality, even when users interoperate at different bit rates.

TWELP scalable

gate.io

An alternative to AMBE+2 DMR / dPMR vocoder, provides highest speech quality, when a voice is more natural, clear and is free of any synthesizing sounds.
Can be used in DMR (ETSI TS 102 361) and dPMR (ETSI TS 102 658) radios as alternative vocoder (instead AMBE+2 vocoder) or as additional vocoder to provide in newest radios main superior mode, providing more high-quality voice communication, keeping simultaneously interoperability with old radios (AMBE+2 based ones).

 
A diagram demonstrates superiority TWELP DMR over AMBE+2 DMR in speech quality in a clear channel. Exact numbers are shown in the table below.
LanguageAMBE+2 DMRTWELP DMR
American 3.085 3.361
Arabic 3.014 3.264
British 3.072 3.220
Chinese 2.979 3.309
Danish 2.941 3.308
Dutch 2.900 3.126
Finnich 2.867 3.068
French 3.117 3.373
German 2.971 3.237
Greek 2.992 3.283
Hindi 3.097 3.276
Hungarian 3.037 3.302
Italian 3.155 3.427
Japanese 3.151 3.389
Norwegian 2.964 3.310
Polish 2.944 3.269
Portuguese 3.175 3.321
Russian 2.980 3.192
Spanish 3.099 3.286
Swedish 3.053 3.293
Average3.0303.281

Superiority of the TWELP DMR vocoder is on average 0.251 PESQ !

Now anyone who would like to use or just to try TWELP vocoder, without paying the cost of a license for large quantities, can order our vocoder as a hardware mini-module based on STM32F chip.

stm32

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Good news for all customers who use CMX7262 chip

Now you can buy a license for the updated TWELP vocoder, interoperable with the vocoder used in CMX7262 chip, as an object library for any target platform even for a small quantity of installations!

The updated vocoder provides much better speech quality (improved up to 0.1 PESQ!) in comparison with the one used in the chip, but is completely interoperable with it in both directions.

Please send your requests to request@dspini.com to get a detailed information and prices.

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Newest transceivers from world leaders use our TWELP vocoder, providing a highest quality and a reliability of the voice communication

PRC 4090

 

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AdaptiveDigitalVoiceTM

Adaptive Digital Voice technology provides a highest possible quality of the voice communication, adapting under fading noisy radio channel with variable SNR. The technology is based on our newest TWELP AMR Robust vocoder, operating at a changeable on the fly bit rate in range 3600 bps down to 300 bps and our newest Adaptive Voice Band modem.

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TWELP Digital Voice in real conditions

Please watch this video up to the end to hear how a Digital Voice with TWELP vocoder is superior to an analogue voice in the channel with a very low SNR. In practice, TWELP vocoder provides reliable clear voice communication in an unworkable analoque channel.

 

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  TWELP vocoders provide a world highest speech quality, operating at twice lower bit rates  

 
The diagram demonstrates a huge superiority of TWELP 2400 bps over MELPe 2400 bps and a closeness (and even superiority for a few languages) to GSM AMR 4750 bps vocoder of the speech quality in a clear channel. Exact numbers are presented in the table below.
LanguageAMR 4750TWELP 2400MELPe 2400
American 3.351 3.330 3.077
Arabic 3.277 3.253 3.053
British 3.272 3.181 3.019
Chinese 3.267 3.307 2.970
Danish 3.311 3.275 3.022
Dutch 3.089 3.114 2.830
Finnich 3.166 3.049 2.791
French 3.277 3.325 3.106
German 3.321 3.183 2.998
Greek 3.206 3.275 3.004
Hindi 3.286 3.246 3.089
Hungarian 3.305 3.279 3.086
Italian 3.462 3.363 3.226
Japanese 3.369 3.407 3.188
Norwegian 3.267 3.286 3.032
Polish 3.263 3.267 3.029
Portuguese 3.377 3.350 3.146
Russian 3.186 3.165 2.952
Spanish 3.343 3.294 3.048
Swedish 3.391 3.269 3.147
Average3.2893.2613.041

Superiority of TWELP 2400 bps vocoder over MELPe 2400 bps is on average 0.220 PESQ and just -0.028 PESQ in comparison with AMR 4750 bps

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 New highest level of speech quality in a very noisy channel

 TWELP 4800 bps Robust vocoder

 TWELP 3600 bps Robust vocoder

 TWELP 2400 bps Robust vocoder

 
BER %MELPe 2400TWELP 2400 Robust (HD)TWELP 2400 Robust (SD)
0 3.041 3.127 3.127
1 2.513 3.039 3.079
2 2.186 2.963 3.006
3 1.940 2.810 2.964
4 1.748 2.582 2.908
5 1.582 2.321 2.842

You can play and listen the short samples of the source speech as well as the speech processed by both vocoders in AWGN channel with BER = 5% for any of 20 languages, using links in the table below.

LanguageSource speechMELPe 2400 (BER = 5%)TWELP 2400 Robust (BER = 5%)
American
Arabic
British
Chinese
Danish
Dutch
Finnich
French
German
Greek
Hindi
Hungarian
Italian
Japanese
Norwegian
Polish
Portuguese
Russian
Spanish
Swedish

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 Our TWELP vocoders are used in the best transceivers from world leaders

4090

icom f8101

barret 4050

rapidm RA7 4050

Leopard 1

Badger

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  Newest TWELP 700 bps vocoder is free of export restrictions and provides a very high speech quality 

 
LanguageTWELP 700 bpsTWELP 600 bpsMELPe 600 bps
American 2.724 2.624 2.397
Arabic 2.603 2.479 2.254
British 2.678 2.577 2.414
Chinese 2.643 2.474 2.189
Danish 2.638 2.497 2.227
Dutch 2.475 2.366 2.173
Finnich 2.472 2.376 2.249
French 2.693 2.524 2.34
German 2.667 2.526 2.287
Greek 2.595 2.472 2.212
Hindi 2.660 2.563 2.403
Hungarian 2.659 2.546 2.359
Italian 2.837 2.720 2.428
Japanese 2.792 2.682 2.436
Norwegian 2.640 2.461 2.225
Polish 2.664 2.519 2.294
Portuguese 2.712 2.589 2.393
Russian 2.591 2.448 2.156
Spanish 2.648 2.537 2.389
Swedish 2.725 2.576 2.430
Average2.65582.52782.3128

Superiority of the TWELP 700 is on average 0.13(!) and 0.34 (!!!) PESQ appropriately