Wireless transmission of audio from or to signal processors of cochlear implants (CIs) is used to improve speech understanding of CI users. This transmission requires wireless communication to exchange the necessary data. Because they are battery powered devices, energy consumption needs to be kept low in CIs, therefore making bitrate reduction of the audio signals necessary. Additionally, low latency is essential. Previously, a codec for the electrodograms of CIs, called the Electrocodec, was proposed. In this work, a subjective evaluation of the Electrocodec is presented, which investigates the impact of the codec on monaural speech performance. The Electrocodec is evaluated with respect to speech recognition and quality in ten CI users and compared to the Opus audio codec. Opus is a low latency and low bitrate audio codec that best met the CI requirements in terms of bandwidth, bitrate, and latency. Achieving equal speech recognition and quality as Opus, the Electrocodec achieves lower mean bitrates than Opus. Actual rates vary from 24.3 up to 53.5 kbit/s, depending on the codec settings. While Opus has a minimum algorithmic latency of 5 ms, the Electrocodec has an algorithmic latency of 0 ms.
References
1.
Allamanche
, E.
, Geiger
, R.
, Herre
, J.
, and Sporer
, T.
(1999
). “MPEG-4 low delay audio coding based on the AAC codec
,” in Proceedings of the 106th AES Convention
, 1 May 1999, Munich, Germany.2.
Boddy
, C.
, and Datta
, G.
(2018
). “The use of the cochlear mini microphone (MM) as a personal radio system (FM) with young children who are deaf
,” Cochlear Implants Int.
19
(6
), 330
–338
.3.
Böhmler
, E.
, Freudenberger
, J.
, and Müller
, M.
(2010
). “Comparison of SBC and G.722 speech codecs for Bluetooth wideband speech transmission
,” in Proceedings of ITG Symposium Speech Communication
, 8 October 2010, Bochum, Germany.4.
Ceulaer
, G.
, Bestel
, J.
, Mülder
, H.
, Goldbeck
, F.
, Janssens de Varebeke
, S.
, and Govaerts
, P.
(2016
). “Speech understanding in noise with the Roger Pen, Naida CI Q70 processor, and integrated Roger 17 receiver in a multi-talker network
,” Eur. Arch. Otorhinolaryngol.
273
, 1107
–1114
.5.
Chen
, F.
, and Loizou
, P.
(2011
). “Predicting the intelligibility of vocoded speech
,” Ear Hear.
32
(3
), 331
–338
.6.
Chen
, J.-H.
, and Thyssen
, J.
(2007
). “The broadvoice speech coding algorithm
,” in Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
, April 15–20, Honolulu, HI, Vol. 4
, pp. IV–537
–IV–540
.7.
Denk
, F.
, Ernst
, S.
, Ewert
, S.
, and Kollmeier
, B.
(2018
). “Adapting hearing devices to the individual ear acoustics: Database and target response correction functions for various device styles
,” Trends Hear.
22
, 233121651877931
.8.
Edelmann
, J.-C.
, and Ussmueller
, T.
(2018
). “Can you hear me now?: Challenges and benefits for connectivity of hearing aids and implants
,” IEEE Microwave Mag.
19
(7
), 30
–42
.9.
Edler
, B.
, Büchner
, A.
, Nogueira
, W.
, and Klefenz
, F.
(2007
). “Cochlear implant, device for generating a control signal for a cochlear implant, device for generating a combination signal and combination signal and corresponding methods
,” International patent WO/2007/033762 (2006-2007).10.
Ernst
, A.
, Baumgaertel
, R.
, Diez
, A.
, and Battmer
, R.-D.
(2019
). “Evaluation of a wireless contralateral routing of signal (CROS) device with the advanced bionics Naída CI Q90 sound processor
,” Cochlear Implants Int.
20
(4
), 182
–189
.11.
European Broadcasting Union
(2008
). “EBU SQAM CD—Sound Quality Assessment Material Recordings for Subjective Tests
,” https://tech.ebu.ch/publications/sqamcd (Last viewed 11.10.2018).12.
European Telecommunications Standards Institute
(2013
). “Electromagnetic compatibility and radio spectrum matters (ERM); system reference document; short range devices (SRD); technical characteristics of wireless aids for hearing impaired people operating in the VHF and UHF frequency range
,” Technical Report ETSI TR 102 791 V1.2.1 (2013-08), https://www.etsi.org/deliver/etsi_tr/102700_102799/102791/01.02.01_60/tr_102791v010201p.pdf (Last viewed 12/21/2020).13.
European Telecommunications Standards Institute
(2018
). “Digital enhanced cordless telecommunications (DECT); study of super wideband codec in DECT for narrowband, wideband and super-wideband audio communication including options of low delay audio connections ( 10 ms framing)
,” Technical Report ETSI TR 103 590 V1.1.1, https://www.etsi.org/deliver/etsi_tr/103500_103599/103590/01.01.01_60/tr_103590v010101p.pdf (Last viewed 11.06.2020).14.
Falk
, T.
, Parsa
, V.
, Santos
, J.
, Arehart
, K.
, Hazrati
, O.
, Huber
, R.
, Kates
, J.
, and Scollie
, S.
(2015
). “Objective quality and intelligibility prediction for users of assistive listening devices
,” IEEE Signal Process. Mag.
32
(2
), 114
–124
.15.
Gajecki
, T.
, and Nogueira
, W.
(2018
). “A synchronized binaural N-of-M sound coding strategy for bilateral cochlear implant users
,” in Proceedings of the 13th ITG Symposium on Speech Communication, VDE
, October 10–12, Oldenburg, Germany, pp. 1
–5
.16.
Gajecki
, T.
, and Nogueira
, W.
(2020
). “The effect of synchronized linked band selection on speech intelligibility of bilateral cochlear implant users
,” Hear. Res.
396
, 108051
.17.
Galster
, J.
(2010
). “A new method for wireless connectivity in hearing aids
,” Hear. J.
63
(36
), 38
–39
.18.
Gifford
, R. H.
, Shallop
, J. K.
, and Peterson
, T. A.
(2008
). “Speech recognition materials and ceiling effects: Considerations for cochlear implant programs
,” Audiol. Neurotol.
13
(3
), 193
–205
.19.
Hinrichs
, R.
, Gajȩcki
, T.
, Ostermann
, J.
, and Nogueira
, W.
(2019
). “Coding of electrical stimulation patterns for binaural sound coding strategies for cochlear implants
,” in Proceedings of the 41st IEEE Engineering in Medicine and Biology Society (EMBC)
, July 23–27, Berlin, pp. 4168
–4172
.20.
Hochmair-Desoyer
, I.
, Schulz
, E.
, Moser
, L.
, and Schmidt
, M.
(1997
). “The HSM sentence test as a tool for evaluating the speech understanding in noise of cochlear implant users
,” Am. J. Otol.
18
(6 Suppl
), S83
.21.
Hoene
, C.
, and Hyder
, M.
(2010
). “Optimally using the Bluetooth subband codec
,” in Proceedings of the IEEE Local Computer Network Conference
, October 10–14, Denver, CO, pp. 356
–359
.22.
23.
IETF Codec Working Group
(2018b
). “Opus-Tools 0.2
,” https://opus-codec.org/release/dev/2018/09/18/opus-tools-0_2.html (Last viewed 10.09.2019).24.
International Telecommuncation Union
(1993
). “ITU Recommendation G.227
,” https://www.itu.int/rec/T-REC-G.227-198811-I/en (Last viewed 10.09.2019).25.
International Telecommuncation Union
(2015
). “ITU-RBS.1534-0 (Method for the subjective assessment of intermediate quality levels of coding systems)
,” https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1534-1-200301-S!!PDF-E.pdf (Last viewed 01.12.2019).26.
Jokisch
, O.
, Maruschke
, M.
, Meszaros
, M.
, and Iaroshenko
, V.
(2016
). “Audio and speech quality survey of the Opus codec in web real-time communication
,” in Proceedings of the 27th Conference on Electronic Speech Signal Processing (ESSV)
, March, Leipzig, Germany, pp. 254
–262
.27.
Kan
, A.
(2018
). “Improving speech recognition in bilateral cochlear implant users by listening with the better ear
,” Trends Hear.
22
, 2331216518772963
.28.
Khalifeh
, A. F.
, Al-Tamimi
, A.
, and Darabkh
, K. A.
(2017
). “Perceptual evaluation of audio quality under lossy networks
,” in Proceedings of the 2017 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET)
, March 22–24, Chennai, India, pp. 939
–943
.29.
Kokkinakis
, K.
, Azimi
, B.
, Hu
, Y.
, and Friedland
, D. R.
(2012
). “Single and multiple microphone noise reduction strategies in cochlear implants
,” Trends Amplif.
16
(2
), 102
–116
.30.
Korhonen
, J.
, and Wang
, Y.
(2005
). “Effect of packet size on loss rate and delay in wireless links
,” in Proceedings of the IEEE Wireless Communications and Networking Conference
, WCNC, March 13–17, New Orleans, LA, Vol. 3
, pp. 1608
–1613
.31.
Kozma-Spytek
, L.
, Tucker
, P.
, and Vogler
, C.
(2019
). “Voice telephony for individuals with hearing loss: The effects of audio bandwidth, bit rate and packet loss
,” in Proceedings of the 21st International ACM SIGACCESS Conference on Computers and Accessibility
, pp. 3
–15
.32.
Kramer
, U.
, Schuller
, G.
, Wabnik
, S.
, Klier
, J.
, and Hirschfeld
, J.
(2004
). “Ultra low delay audio coding with constant bit rate
,” in 117th Audio Engineering Society Convention
, October 28–31, San Francisco.33.
Kressner
, A. A.
, Anderson
, D. V.
, and Rozell
, C. J.
(2011
). “Robustness of the hearing aid speech quality index (HASQI)
,” in Proceedings of the 2011 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA)
, pp. 209
–212
.34.
Kressner
, A.
, May
, T.
, and Dau
, T.
(2019
). “Effect of noise reduction gain errors on simulated cochlear implant speech intelligibility
,” Trends Hear.
23
, 233121651982593
.35.
Li
, M.
, and Kleijn
, W.
(2007
). “A low-delay audio coder with constrained-entropy quantization
,” in Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics
, October 21–24, New Paltz, NY, pp. 191
–194
.36.
Lopez-Poveda
, E.
, Eustaquio-Martin
, A.
, Stohl
, J.
, Wolford
, R.
, Schatzer
, R.
, and Wilson
, B. S.
(2016
). “A binaural cochlear implant sound coding strategy inspired by the contralateral medial olivocochlear reflex
,” Ear Hear.
37
(3
), 138
–148
.37.
Mehrkian
, S.
, Bayat
, Z.
, Javanbakht
, M.
, Emamdjomeh
, H.
, and Bakhshi
, E.
(2019
). “Effect of wireless remote microphone application on speech discrimination in noise in children with cochlear implants
,” Int. J. Pediatr. Otorhinolaryngol.
125
, 192
–195
.38.
Nogueira
, W.
, Abel
, J.
, and Fingscheidt
, T.
(2019
). “Artificial speech bandwidth extension improves telephone speech intelligibility and quality in cochlear implant users
,” J. Acoust. Soc. Am.
145
(3
), 1640
–1649
.39.
Nogueira
, W.
, Büchner
, A.
, Lenarz
, T.
, and Edler
, B.
(2005
). “A psychoacoustic ‘NofM’-type speech coding strategy for cochlear implants
,” EURASIP J. Appl. Signal Process.
2005
, 3044
–3059
.40.
Ostergaard
, J.
, Quevedo
, D.
, and Jensen
, J.
(2009
). “Low delay moving-horizon multiple-description audio coding for wireless hearing aids
,” in Proceedings of the 2009 IEEE International Conference on Acoustics, Speech and Signal Processing
, April 19–24, Taipei, Taiwan, pp. 21
–24
.41.
Oticon
(2019
). “Oticon CROS
” https://wdh01.azureedge.net/-/media/oticon/main/pdf/germany/cros/pbr/65949de_pbr_promotional_sheet_oticon_cros.pdf?&la=de-de&rev=03B9&hash=AEA390E8EA49233F01CB28085C65F1AB (Last viewed 21.12.2020).42.
Pal
, A.
, and Kant
, K.
(2019
). “NFMI: Connectivity for short-range IoT applications
,” Computer
52
(2
), 63
–67
.43.
Phonak
(2012
). “Binaural voicestream technology
,” https://pdfs.semanticscholar.org/b12a/16d5808e841d0a1cf41be9051ce40edc7cda.pdf (Last viewed 31.03.2020).44.
Phonak
(2016
). Technical information Naída Link CROS
, https://advancedbionics.com/content/dam/advancedbionics/Documents/Regional/DK/Datasheets/Datasheet_Phonak_Naida_Link_CROS_210x297_GB_V1.00.pdf (Last viewed 06.05.2020).45.
Preihs
, S.
, Lamprecht
, T.
, and Ostermann
, J.
(2016
). “Error robust low delay audio coding using spherical logarithmic quantization
,” in Proceedings of the 24th European Signal Processing Conference (EUSIPCO)
, pp. 1970
–1974
.46.
Qazi
, O.
, van Dijk
, B.
, Moonen
, M.
, and Wouters
, J.
(2013
). “Understanding the effect of noise on electrical stimulation sequences in cochlear implants and its impact on speech intelligibility
,” Hear. Res.
299
, 79
–87
.47.
48.
Rämö
, A.
, and Toukomaa
, H.
(2011
). “Voice quality characterization of IETF Opus codec
,” in Proceedings of the 12th Annual Conference of the International Speech Communication Association (INTERSPEECH)
, August, Florence, Italy, pp. 2541
–2544
.49.
Roy
, O.
, and Vetterli
, M.
(2007
). “Distributed spatial audio coding in wireless hearing aids
,” in Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics
, October 21–24, New Paltz, NY, pp. 227
–230
.50.
Shannon
, C. E.
(1949
). “Communication in the presence of noise
,” Proc. IRE
37
(1
), 10
–21
.51.
Taal
, C.
, Hendriks
, R.
, Heusdens
, R.
, and Jensen
, J.
(2010
). “A short-time objective intelligibility measure for time-frequency weighted noisy speech
,” in Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing
, March 14–19, Dallas, TX, pp. 4214
–4217
.52.
Taal
, C. H.
, Hendriks
, R. C.
, Heusdens
, R.
, and Jensen
, J.
(2011
). “An algorithm for intelligibility prediction of time-frequency weighted noisy speech
,” IEEE Trans. Audio Speech Lang. Process.
19
(7
), 2125
–2136
.53.
Valin
, J.-M.
, Maxwell
, G.
, Terriberry
, T.
, and Vos
, K.
(2013
). “High-quality, low-delay music coding in the Opus codec
,” Proceedings of the 135th Audio Engineering Society Convention 2013
, October 17–20, New York, pp. 73
–82
.54.
Watkins
, G.
, Swanson
, B.
, and Suaning
, G.
(2018
). “An evaluation of output signal to noise ratio as a predictor of cochlear implant speech intelligibility
,” Ear Hear.
39
(5
), 958
–968
.55.
Weder
, S.
, Kompis
, M.
, Caversaccio
, M.
, and Stieger
, C.
(2015
). “Benefit of a contralateral routing of signal device for unilateral cochlear implant users
,” Audiol. Neurotol.
20
(2
), 73
–80
.56.
Wilson
, R.
, McArdle
, R.
, and Smith
, S.
(2007
). “An evaluation of the BKB-SIN, HINT, QUICKSIN, and WIN materials on listeners with normal hearing and listeners with hearing loss
,” J. Speech Lang. Hear. Res.
50
(4
), 844
–856
.57.
Wolfe
, J.
, Duke
, M.
, and Schafer
, E.
(2016a
). “Speech recognition of bimodal cochlear implant recipients using a wireless audio streaming accessory for the telephone
,” Otol. Neurotol.
37
, e20
–e25
.58.
Wolfe
, J.
, Duke
, M.
, Schafer
, E.
, Cire
, G.
, Menapace
, C.
, and O'Neil
, L.
(2016b
). “Evaluation of a wireless audio streaming accessory to improve mobile telephone performance of cochlear implant users
,” Int. J. Audiol.
55
(2
), 75
–82
.59.
Wolfe
, J.
, Morais
, M.
, and Schafer
, E.
(2015
). “Improving hearing performance for cochlear implant recipients with use of a digital, wireless, remote-microphone, audio-streaming accessory
,” J. Am. Acad. Audiol.
26
(6
), 532
–539
.60.
Wouters
, J.
, McDermott
, H. J.
, and Francart
, T.
(2015
). “Sound coding in cochlear implants: From electric pulses to hearing
,” IEEE Signal Process. Mag.
32
(2
), 67
–80
.61.
Zeitler
, D. M.
, Kessler
, M. A.
, Terushkin
, V.
, Roland
, T.
, Jr., Svirsky
, M. A.
, Lalwani
, A. K.
, and Waltzman
, S.
(2008
). “Speech perception benefits of sequential bilateral cochlear implantation in children and adults: A retrospective analysis
,” Audiol. Neurotol.
13
(3
), 314
–325
.62.
Zirn
, S.
, Arndt
, S.
, Aschendorff
, A.
, and Wesarg
, T.
(2015
). “Interaural stimulation timing in single sided deaf cochlear implant users
,” Hear. Res.
328
, 148
–156
.© 2021 Acoustical Society of America.
2021
Acoustical Society of America
You do not currently have access to this content.