How much delay does Wi-Fi streaming add, and when does it matter?

Why it matters

Audio over Wi-Fi passes a venue's sound through an audio server and the venue's network to an app on listeners' phones or to Wi-Fi receivers, and from a phone on to headphones, a neckloop, or hearing aids and implants by Bluetooth^1,2. Every link adds delay, and the delays add up from the microphone to the hearing instrument^3,4.

Listeners who also hear the room may hear the late stream as an echo or a mushy sound⁵, and listeners who watch the talker or a screen may see lips out of step with the sound^6,4,7. Both the size of the delay and the setting therefore bear on where a Wi-Fi system can serve as assistive listening^1,5.

What the evidence shows

Stated and measured delay

• Makers state 40-60 ms. Sennheiser's data sheet gives 40-60 ms on average for its app⁸, and its product page "as low as 25 ms, depending on the network and device used"; the same page's feature list gives 40-60 ms for the stream and 25 ms for the talk-back microphone⁹. Listen Technologies gives 40-60 ms "dependent on network, traffic, and QOS" for its system with its own Wi-Fi receiver, while the architect's specification on the same page says under 40 ms "on a good and properly configured network"¹⁰. None of these figures comes with a method, and Williams AV's network guide gives no latency figure².
• A maker's earlier phone figures were higher. Listen's 2017 technical note gave 170-214 ms on Apple and 252-463 ms on Android devices, and said latency varies greatly with the phone's make and model⁴.
• Independent accounts. A theatre consultancy reports measuring over 130 ms with standard smartphones, without naming the system, phones, number of tests or method¹¹. Pilot work for an AGE-WELL Canada-funded university concert study, with hearing aids and fittings provided by Sonova Canada, found about 350 ms over a Wi-Fi-to-phone-to-hearing-aid path; the number of pilot measurements is not stated¹².
• Advocates' ranges. The Center for Hearing Access says these systems "typically have 100-500+ ms latency"⁵; its quick guide gives 200-300+ ms, against about 1-20 ms for loops and infrared, 1-30 ms for FM and about 36-100+ ms for Auracast¹³. RNID states that Wi-Fi networks "often add too much delay to the signal"¹⁴, and IAHA, an industry association, that the delay varies with the environment, device and configuration¹.
• Listeners' ratings. In an advocacy committee's self-selected survey of 1,519 people, with funding unstated, 251 respondents rated Wi-Fi delay: 119 were not conscious of it, 88 found it distracting and 44 objectionable. Only 217 answered yes to the separate question about having used Wi-Fi audio, so these counts do not establish a consistent sample of experienced users. Recruitment was through hearing-loss networks and respondents were mostly older people with severe to profound loss^15,16.

What adds the delay

• The access point and the network. Listen's 2017 note attributes most of the delay to the access point's transmission and the phone's processing and playback, and names interference from nearby access points and encryption as adding delay⁴. In an independent study supported by Chinese government research grants, covering more than 47,000 devices on one university campus network, a ping-based estimate of wireless-hop round-trip delay was about 3 ms at the median, 20 ms at the 90th percentile and 250 ms at the 99th; busy channels, many devices online and a poor signal-to-noise ratio were the most informative signs of a long delay. The method used a second ping after waking the device and averaged six readings per minute. This was a general data-network study, with no audio-streaming or assistive-listening test¹⁷.
• Buffering and power saving. Williams AV says its live streams buffer only 2-3 packets ahead to avoid lip-sync delay, so a lost packet is heard as a drop-out, and that higher DTIM settings make the audio arrive in bursts². An IETF document notes that when any connected device uses power-save mode, the access point holds multicast frames until the next DTIM beacon¹⁸. One venue tells listeners whose echo grows during a session to pause and restart the stream to clear the buffering, which may need repeating on older phones¹⁹.
• The phone. Apple devices were faster than Android devices, and older models slower, in Listen's 2017 note⁴; the same venue says apps running in the background can add to the latency¹⁹.
• Bluetooth to earbuds or hearing aids. In a hearing-app maker's 2017 measurements, sending live sound from an iPhone app to Bluetooth earbuds took 192 to 295 ms, against 16 ms with wired earphones. The 192 ms result used the earbud microphone, the 258 and 295 ms results used phone microphones, and the 16 ms wired result used a wired-earphone microphone and a different app. With no stated repetition count and different inputs, these illustrate shared playback paths rather than a venue Wi-Fi system or Bluetooth transport delay alone⁷. Listen's manual says Bluetooth devices are "not recommended due to the significant latency that it can introduce" when lip sync matters²⁰, and Sennheiser's app listing recommends wired headphones or induction ear hooks "to avoid audio delay through Bluetooth"²¹. A maker's white paper, HLAA and a UK charity also say Bluetooth devices or streamers can add delay^22,23,6.

How much delay listeners tolerate

• Alongside room sound, tens of milliseconds. A position paper describes a second copy of a sound as heard as an echo above about 30 ms²⁴. The UK code of practice asks for 30 ms or less between the assistive signal and the acoustic sound where possible, with 40 ms the limit, counting the whole chain²⁵; a Swiss expert gives about 40 ms²⁶, and the Center for Hearing Access applies 30-40 ms, marked as under review, to end-to-end latency³. Much of the research on how much delay listeners tolerate tested short hearing-aid processing delays; it is set out in the delay question^27,24.
• A late copy of speech harms understanding, more so with hearing loss. In an independent university study, whose abstract gives neither sample size nor a named funder, with speech plus one delayed copy of it from the same direction, the copy was fully integrated up to at least 25 ms, intelligibility then declined gradually, and at 200 ms the copy made it worse than the direct sound alone²⁸. In an independent study funded by the German Research Foundation and Klaus Tschira Foundation, 14 older listeners with mild to moderate hearing loss, compared with a younger normal-hearing group from earlier work, heard an equally loud copy 200 ms late and needed 6.5 dB more signal-to-noise ratio on average, against 3.4 dB for young normal-hearing listeners²⁹.
• A much louder late copy did little harm. When the 200 ms copy had 2.5 times the amplitude of the direct sound, every listener with hearing loss scored close to their result without it²⁹. One venue says muting hearing aid microphones, which blocks or minimises the loudspeaker sound, "eliminates the echo"¹⁹. The Center for Hearing Access notes that hearing devices cannot use a "Mic + Wi-Fi" setting⁵, and with open fittings room sound reaches the ear through the vent³⁰.
• Lip-reading tolerates more lag than echo does. In an independent NSF-funded study of 9 normal-hearing listeners, intelligibility of filtered speech with the talker's face visible stayed relatively stable with the audio up to about 160-200 ms late³¹. A study from the manufacturer Starkey's research centre found synchrony windows of a few hundred milliseconds in 11 listeners with moderate to severe hearing loss and 11 with normal hearing³². Television viewers detected sound lagging the picture at about 125 ms and found it unacceptable beyond about 185 ms³³. The EBU recommends keeping sound no more than 60 ms behind the picture at transmission³⁴, and the UK code asks for audio within 50 ms of a video display of the talker²⁵.

Where sources say Wi-Fi suits, and where not

• No live sound competing. The Center for Hearing Access says audio over Wi-Fi works well when the live sound is off, giving TVs in sports bars and fitness centres as examples⁵. A UK charity says Wi-Fi systems are found in gyms, sports bars and churches, especially where listeners choose between channels⁶. Listen's 2017 note was written for TV audio and says a TV's own input lag, sometimes over 100 ms, affects how well sound and picture line up⁴.
• Live speech in the room. The Center for Hearing Access quotes a hearing-technology professional who switched a system off because the stream and the room sound together created reverberation⁵. The UK charity says the delay can be confusing in small rooms or when lipreading⁶, and HLAA that the latency of Wi-Fi systems may prove challenging in some situations²³. Australia's standard has appendix headings on why low latency is critical and why mobile phones are not suitable as receivers; the reasoning is in the paid text³⁵.
• Live events in use. One venue streams live lectures and performances over Wi-Fi in its amphitheater and halls and reports from user feedback that the system works best for patrons with moderate to severe hearing loss¹⁹. Listen presents its receiver as ideal for classrooms, places of worship and theatres¹⁰.

Where sources disagree

On the size of the delay, makers' 40-60 ms, with best cases of 25 ms or under 40 ms^8,9,10, stands against a maker's own 2017 phone figures of 170-463 ms⁴, the consultancy's over 130 ms to phones¹¹, the pilot's 350 ms through hearing aids¹² and advocates' 100-500+ or 200-300+ ms^5,13. Most of these figures come without the measurement points, phones, listening path or network load behind them, so they cannot be compared directly^4,8,5.

On Bluetooth, Sennheiser's specification says its system shall support all wireless and wired headphones, hearing aids and cochlear implants⁸, and one venue invites listeners to use Bluetooth hearing aids¹⁹, while Listen's manual and Sennheiser's app listing recommend wired listening to avoid Bluetooth delay, Listen's where lip sync matters^20,21.

On suitability for live speech, the Center for Hearing Access says audio over Wi-Fi works well where the live sound is off and lists concerns where it is on⁵, while Listen presents its system for classrooms, places of worship and theatres¹⁰ and one venue uses Wi-Fi for live events¹⁹. In the survey, 119 of the 251 respondents who rated the delay were not conscious of it¹⁵.

The research points in different directions on hearing loss. In an independent study funded by EPSRC and EU grants, 20 listeners with mild to moderate loss tolerated more processing delay than 20 normal-hearing listeners in two of three voice conditions, in tests up to 50 ms²⁷. Another independent study, with funding not identified, found higher echo thresholds for short noise bursts in 9 listeners with hearing loss than in 8 with normal hearing³⁶; yet with a copy of speech 200 ms late, listeners with hearing loss lost more intelligibility than normal-hearing listeners²⁹. The studies measured different things (annoyance, echo detection, understanding) at very different delays.

Which tolerance applies also differs by setting. In television tests, viewers detected late sound at about 125 ms and found it unacceptable beyond about 185 ms³³, and in a lip-reading test intelligibility held up to about 160-200 ms of lag³¹; the EBU recommends a maximum lag of 60 ms³⁴, and guidance for assistive listening heard alongside the room sound 30-40 ms^25,26,3.

What would settle it

Independent measurements of current Wi-Fi systems from the venue's mixing desk to the listener's ear, with the method stated: across common iPhone and Android models of different ages and dedicated receivers; with wired headphones, neckloops, Bluetooth earbuds and Bluetooth hearing aids; in empty and full venues with busy networks; and over a whole session, to show whether the delay drifts. The sources found give makers' figures without methods, a consultancy's unspecified phone measurements and one pilot figure; these do not establish how delay varies across current devices and occupied venues^{4,10,11,12,19}.

Listening tests with hearing-aid and implant users in a real room, with a stream arriving 50 to 400 ms after the room sound, open and closed fittings, and hearing-aid microphones on and muted, measuring understanding, listening effort and preference. The laboratory studies cited here stop at 200 ms and use no assistive listening system^28,29. IAHA reports no peer-reviewed studies of Wi-Fi systems for people with hearing loss, and the Center for Hearing Access says no third-party, peer-reviewed research shows they work well^1,5. Lip-sync tests with viewers with hearing loss at the delays Wi-Fi adds to a television picture would show whether the general-audience limits apply^33,34.

Planning while it is open

• Check whether listeners will also hear live sound in the room; the Center for Hearing Access says audio over Wi-Fi works well where the live sound is off, as with TVs in sports bars and fitness centres⁵.
• At commissioning, open each channel on phones and on receivers and check the latency, as one maker's manual asks²⁰, counting the whole chain to the listener's ear^25,3. Include Android and older phones, which were slower in a maker's tests⁴.
• Where lip sync or room sound matters, recommend wired headphones, neckloops or induction ear hooks over Bluetooth, as two makers advise^20,21.
• Set up the network for live audio as makers' guides list: quality-of-service priority for the audio, the lowest possible DTIM setting, a clear channel and an access point in the room^2,20,4.
• Tell listeners what one venue suggests against echo: mute hearing-aid microphones where the hearing aid's app allows, close other apps, and pause and restart the stream if the echo grows¹⁹.
• Where the stream arrives before the picture or the room sound, add delay at the server to line it up; one maker's server allows up to 3 seconds^20,4. Where a video display shows the talker, keep the audio within 50 ms of the picture, as the UK code asks²⁵.

Sources

1. Audio Over Wi-Fi Assistive Listening Systems. International Association for Hearing Accessibility (IAHA), undated (read 9 October 2026). Trade body (IAHA; its members include manufacturers of assistive listening technologies and other organisations that create or install assistive listening systems, as well as groups supporting people with hearing loss; its funding is not stated) ↩︎ https://iaha-global.com/assistive-listening-technologies/audio-over-wifi/
2. WaveCAST Network Guide for Consultants and IT Professionals (TCH 040I). Williams AV, 2024. Manufacturer (Williams AV, maker of the WaveCAST Wi-Fi system, which also sells FM, infrared and Auracast assistive listening systems) ↩︎ https://williamsav.com/wp-content/uploads/2020/04/TCH-040I-Wavecast-Network-Guide-1.pdf
3. What is needed for Auracast streamed assistive listening systems to be available and usable. Center for Hearing Access (reviewed by Juliette Sterkens, AuD). Center for Hearing Access, The John G. Shedd Institute, 15 December 2024. Nonprofit advocacy (Center for Hearing Access, an initiative of The John G. Shedd Institute for the Arts; it states that it accepts no donations from hearing-related vendors) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/What-is-needed-for-Auracast-streamed-ALS-to-be-available-and-usable.pdf
4. Understanding & Minimizing Wi-Fi Latency (Listen Tech-Note LTN0012). Listen Technologies, 27 April 2017. Manufacturer (Listen Technologies, maker of the ListenWiFi system described) ↩︎ https://www.listentech.com/wp-content/uploads/2017/05/LTN0012_Wifi-Latency-Tech-Note_042717.pdf
5. Audio Over Wi-Fi Assistive Listening System. Center for Hearing Access. Center for Hearing Access, The John G. Shedd Institute for the Arts, undated (read 9 October 2026). Nonprofit advocacy (Center for Hearing Access, an initiative of The John G. Shedd Institute for the Arts; it asks for donations and states that it accepts none from hearing-related vendors) ↩︎ https://centerforhearingaccess.org/wi-fi/
6. Other assistive listening systems. Hearing Dogs for Deaf People, undated (read 9 October 2026). Nonprofit advocacy (Hearing Dogs for Deaf People, a UK charity whose support pages include Hearing Link Services; the page thanks the loop and Auracast maker Ampetronic for help creating it, and Ampetronic's owner, Allvida, also owns the Wi-Fi system maker Listen Technologies) ↩︎ https://www.hearingdogs.org.uk/support/living/assistive-technology/systems
7. Can Apple AirPods be used as hearing aids?. Einhorn R. Hearing Review 24(10):24-25, 22 September 2017. Manufacturer (the measurements are Jacoti's, a maker of hearing apps, one of which was among those tested; the author states being a consultant for Jacoti and thanks its software team for the data) ↩︎ https://hearingreview.com/hearing-products/hearing-aids/can-apple-airpods-used-hearing-aids
8. System Specification (V1.2): MobileConnect Assistive Listening. Sennheiser. Sennheiser electronic GmbH & Co. KG, 2023. Manufacturer (Sennheiser, maker of the MobileConnect Wi-Fi system) ↩︎ https://assets.sennheiser.com/download/assets/MobileConnect_System_Specification_v1.2_EN.pdf/ea3cf3b2e7b711f097eaea55b5d2fb86
9. MobileConnect App for Audience Engagement. Sennheiser. Sennheiser (product page), undated (read 9 October 2026). Manufacturer (Sennheiser, maker of the MobileConnect Wi-Fi system) ↩︎ https://www.sennheiser.com/en-us/catalog/applications/assistive-listening-and-audience-engagement/mobileconnect-app-223344/mobileconnect-app-product-123456
10. ListenWIFI Wi-Fi Audio Receiver (LWR-1050). Listen Technologies. Listen Technologies (product page), 1 February 2024. Manufacturer (Listen Technologies, maker of the ListenWIFI system and receiver described, which also sells RF/FM, infrared, hearing loop and Auracast assistive listening products) ↩︎ https://www.listentech.com/shop/product/listenwifi-wi-fi-audio-receiver/
11. Assistive Listening - Demystified. Lerman K (Theatreplan). Theatreplan (news blog), 29 April 2025. Independent (Theatreplan, a UK theatre planning consultancy; written by its consultant Kit Lerman; no funding is stated) ↩︎ https://theatreplan.com/news/assistive-listening-demystified
12. Evaluating a hearing loop implementation for live orchestral music. McWeeny S, Trainor LJ, Armstrong S, Bosnyak D, Tawfik H, Bruce IC. Ear and Hearing 46(3):808-816, 27 January 2025. Independent (McMaster University; AGE-WELL Canada grant); in-kind hearing aids and fittings from Sonova Canada ↩︎ https://pubmed.ncbi.nlm.nih.gov/39868727/
13. Assistive Listening Systems Quick Guide. Center for Hearing Access (reviewed by Juliette Sterkens, AuD). Center for Hearing Access, The John G. Shedd Institute, 29 October 2025. Nonprofit advocacy (Center for Hearing Access, an initiative of The John G. Shedd Institute for the Arts; it states that it accepts no donations from hearing-related vendors) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/Assistive-Listening-Systems-Quick-Guide.pdf
14. Infrared, FM and Audio Over WiFi. RNID. RNID (Royal National Institute for Deaf People), 27 May 2026. Nonprofit advocacy (RNID, UK charity) ↩︎ https://rnid.org.uk/information-and-support/technology-and-products/assistive-listening/infrared-fm-and-audio-over-wifi/
15. CCAA Survey on Assistive Communication Technology: Graphs. Committee for Communication Access in America. Committee for Communication Access in America (ccaa.name), 2023. Nonprofit advocacy (an ad hoc committee of hearing-loss advocates chaired by Stephen O. Frazier (Loop New Mexico; a founding member of HLAA's Get in the Hearing Loop initiative), among them hearing loop advocates David Myers and Juliette Sterkens; funding not stated; the survey page says the responses were recorded by the Frost Center for Data and Social Research at Hope College) ↩︎ https://www.ccaa.name/CCAA_Graphs.pdf
16. Consumer use of and preferences for assistive communication technology in public places. Committee for Communication Access in America (Frazier SO, Bailey A, Cadwell B, Clifford C, Liebe K, Myers D, Sterkens J). Committee for Communication Access in America, 8 January 2024. Nonprofit advocacy (an ad hoc committee of hearing-loss advocates, chaired by Stephen O. Frazier (Loop New Mexico; a founding member of HLAA's Get in the Hearing Loop initiative), the report's correspondence author; funding not stated; data collected and analysed by the Frost Center for Data and Social Research at Hope College. The committee's site lists David Myers (founder of hearingloop.org) and Juliette Sterkens (HLAA hearing loop advocate) among its members, with Abram Bailey (founder of HearingTracker), Blake Cadwell (founder and CEO of Soundly), Kevin Liebe (hearinghealthmatters.org) and Carol Clifford (audiologist, former ReSound training director)) ↩︎ https://www.ccaa.name/Report_Final_1-12-24.pdf
17. Characterizing and improving WiFi latency in large-scale operational networks. Sui K, Zhou M, Liu D, Ma M, Pei D, Zhao Y, Li Z, Moscibroda T. MobiSys '16 (ACM International Conference on Mobile Systems, Applications, and Services), Singapore, June 2016. Independent (Tsinghua University, with one author from Microsoft Research; supported by National Natural Science Foundation of China and other Chinese government research grants) ↩︎ https://dl.acm.org/doi/10.1145/2906388.2906393
18. Multicast Considerations over IEEE 802 Wireless Media (RFC 9119). Perkins C, McBride M, Stanley D, Kumari W, Zúñiga JC. Internet Engineering Task Force (IETF), RFC Editor, October 2021. Standards body (IETF; an Informational RFC that represents IETF consensus but is not a standard; the authors were with Lupin Lodge, Futurewei, HPE, Google and SIGFOX) ↩︎ https://www.rfc-editor.org/rfc/rfc9119.html
19. Wi-Fi Based Assistive Listening System (beta testing page). Chautauqua Institution. Chautauqua Institution (visitor information page), undated (read 9 October 2026). Independent (Chautauqua Institution, a nonprofit arts and education centre in New York State that runs the Listen Wi-Fi system it describes; the advice draws on its own user feedback) ↩︎ https://chq.org/visit/explore-the-grounds-and-gardens/accessibility/wi-fi-based-assistive-listening-system-beta-testing
20. ListenWIFI System Manual. Listen Technologies, 15 January 2026. Manufacturer (Listen Technologies, maker of the ListenWIFI system described, which also sells RF/FM, infrared, hearing loop and Auracast assistive listening products) ↩︎ https://www.listentech.com/wp-content/uploads/2024/07/ListenWIFI-System-Manual-2026.01.15-V5.pdf
21. Sennheiser MobileConnect (App Store listing, version 6.3.1). Sennheiser. Apple App Store (seller: Sennheiser electronic SE & Co. KG), 4 May 2026. Manufacturer (Sennheiser, maker of the MobileConnect Wi-Fi system; the listing and its privacy label are written by the developer) ↩︎ https://apps.apple.com/us/app/sennheiser-mobileconnect/id848127271
22. Understanding the Assistive Listening Americans with Disabilities Act. Listen Technologies, 25 October 2023. Manufacturer (Listen Technologies, which sells RF/FM, infrared, hearing loop, Wi-Fi and Auracast assistive listening products; owned since February 2023 by Allvida, which also owns the hearing-loop maker Ampetronic) ↩︎ https://www.listentech.com/wp-content/uploads/2019/07/ADA-White-Paper-2023-10-25-vA1-WEB.pdf
23. Coupling Options: Ways to Connect to Assistive Listening System Audio. Kaneb A (credited on the chart). Hearing Loss Association of America (HLAA), 2026. Nonprofit advocacy (Hearing Loss Association of America, a US consumer organisation for people with hearing loss; the chart is credited to Andrea Kaneb and names no funder) ↩︎ https://www.hearingloss.org/wp-content/uploads/documents/advocacy-resources/hlaa-coupling-options-als-chart.pdf
24. Requirements for mass adoption of assistive listening technology by the general public. Kaufmann TB, Foroogozar M, Liss J, Berisha V. ICASSP 2023 Workshops, IEEE (arXiv 2303.02523), 3 May 2023. Independent (Arizona State University) ↩︎ https://arxiv.org/abs/2303.02523
25. Code of Practice for the Design and Operation of Assistive Listening Systems, Issue 1. Audio Industries Committee on Assistive Listening Systems. Audio Industries Committee on Assistive Listening Systems; distributed by the Institute of Sound, Communications and Visual Engineers (UK), December 2023. Trade body (Audio Industries Committee on Assistive Listening Systems, an audio industry committee; distributed by the Institute of Sound, Communications and Visual Engineers; the code names no funder) ↩︎ https://iscve.org.uk/standards/assistive-listening-guide-and-code-of-practice/
26. Bluetooth Auracast in theaters and event venues. Graf B (Pro Audito Schweiz). Proscenium no. 3, pp. 10-11, Swiss Association of Technical Stage and Event Industry; English reprint by the Center for Hearing Access, September 2026. Nonprofit advocacy (Pro Audito Schweiz, Swiss hearing-loss association) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/Proscenium-Technical-article-Bluetooth-Auracast-in-theaters-and-event-venues-1.pdf
27. Tolerable delay for speech production and perception: effects of hearing ability and experience with hearing aids. Goehring T, Chapman JL, Bleeck S, Monaghan JJM. International Journal of Audiology 57(1):61-68, 2018. Independent (University of Southampton; EPSRC and EU Seventh Framework Programme grants) ↩︎ https://pubmed.ncbi.nlm.nih.gov/28838277/
28. Effects of spatial and temporal integration of a single early reflection on speech intelligibility. Warzybok A, Rennies J, Brand T, Doclo S, Kollmeier B. Journal of the Acoustical Society of America 133(1):269-282, January 2013. Independent (Medical Physics, University of Oldenburg; the abstract names no funder, and PubMed indexes the work as non-US government research support) ↩︎ https://pubmed.ncbi.nlm.nih.gov/23297901/
29. Spatio-temporal integration of speech reflections in hearing-impaired listeners. Rennies J, Warzybok A, Kollmeier B, Brand T. Trends in Hearing 26:23312165221143901, 19 December 2022. Independent (Fraunhofer Institute for Digital Media Technology IDMT and University of Oldenburg, Cluster of Excellence Hearing4all; funded by the German Research Foundation (DFG, SFB 1330) and the Klaus Tschira Foundation; the authors declare no conflicts of interest) ↩︎ https://pmc.ncbi.nlm.nih.gov/articles/PMC9772954/
30. Hearing aids: what works well and what can be improved. Moore BCJ. Journal of the Association for Research in Otolaryngology 27:123-135, 13 February 2026. Independent (University of Cambridge; UK research council grant) ↩︎ https://link.springer.com/article/10.1007/s10162-026-01031-5
31. Speech intelligibility derived from asynchronous processing of auditory-visual information. Grant KW, Greenberg S. Proceedings of Auditory-Visual Speech Processing (AVSP) 2001, pp. 132-137 (ISCA Archive), September 2001. Independent (Walter Reed Army Medical Center and International Computer Science Institute; US National Science Foundation grant) ↩︎ https://www.isca-archive.org/avsp_2001/grant01_avsp.html
32. Audiovisual asynchrony detection and speech intelligibility in noise with moderate to severe sensorineural hearing impairment. Başkent D, Bazo D. Ear and Hearing 32(5):582-592, September 2011. Manufacturer (Starkey Hearing Research Center affiliation) ↩︎ https://pubmed.ncbi.nlm.nih.gov/21389856/
33. Relative timing of sound and vision for broadcasting (Recommendation ITU-R BT.1359-1). International Telecommunication Union, Radiocommunication Sector (ITU-R). ITU-R, November 1998. Standards body (International Telecommunication Union, Radiocommunication Sector) ↩︎ https://www.itu.int/rec/R-REC-BT.1359-1-199811-I/en
34. The relative timing of the sound and vision components of a television signal (EBU Recommendation R37-2007). European Broadcasting Union (EBU). European Broadcasting Union, Geneva, 27 February 2007. Standards body (European Broadcasting Union, an association of public service media organisations; an EBU technical recommendation) ↩︎ https://tech.ebu.ch/publications/r037
35. AS 1428.5:2021 Design for access and mobility, Part 5: Communication for people who are deaf or hearing impaired. Standards Australia. Standards Australia (Standards Store), 3 September 2021. Standards body (Standards Australia) ↩︎ https://store.standards.org.au/product/as-1428-5-2021
36. Effects of hearing loss on echo thresholds. Roberts RA, Besing J, Koehnke J. Ear and Hearing 23(4):349-357, August 2002. Independent (University of South Florida) ↩︎ https://pubmed.ncbi.nlm.nih.gov/12195177

Change log

• 10 October 2026Published with 35 sources.
• 13 October 2026Added the existing consultancy measurement, qualified the survey sample and clarified study scope and funding; now cites 36 sources.
• 13 October 2026Corrected the campus delay measurement definition and microphone and app differences in the earbud comparison.

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