AI tools for podcast accessibility with transcription and multilingual support

Accessible podcasts are no longer an ethical upgrade — as of June 2025 they’re a European legal requirement under the European Accessibility Act, and as of April 2026 US states and municipalities above 50 k population are bound under the revised ADA Title II rule. This playbook is how Fora Soft engineers ship production-grade accessibility into podcast and audio-streaming platforms: the ASR + diarization + translation stack, the Podcasting 2.0 namespace, the cost model, the compliance matrix, and the 10–14-week rollout path.

Key takeaways

  • Accessibility is compliance-driven in 2026. EAA (live June 28, 2025, fines up to €1 M), ADA Title II (April 24, 2026 deadline for larger public entities), WCAG 2.2, CVAA, UK Equality Act.
  • ASR has consolidated to three serious options. Deepgram Nova-3, AssemblyAI Universal-2, OpenAI Whisper v3. Lab WER numbers (5–8%) are marketing; real-world podcast WER lands at 12–20% with domain jargon and multi-speaker audio.
  • Podcasting 2.0 is the accessibility delivery layer. <podcast:transcript>, <podcast:chapters>, <podcast:person>, <podcast:soundbite> — Apple Podcasts accepts creator VTT/SRT via RSS; Fountain, Podverse, Podcast Addict, Overcast (beta March 2026) render them natively.
  • Full accessibility suite costs $0.80–$2.30 per episode hour. That’s ASR + diarization + 3-language translation + AI summary + chapters. Payback comes from SEO (+6.68% search ranking, +16% backlinks) and from the 33% engagement lift seen in vision-disabled listener cohorts.
  • Ship transcripts first, dubs second, audio-description third. Most podcast products under-invest in the last mile — the web player’s screen-reader, keyboard nav, and high-contrast mode — and that’s where auditors will find the failing.

Why Fora Soft wrote this playbook

Fora Soft has shipped audio and video streaming platforms for 20 years. In 2024–2026 we added accessibility layers to three podcast and audio-learning products: an EdTech platform that ingests lectures and serves them as podcasts with synchronized transcripts, a corporate-training platform subject to EAA review, and a multi-language interview podcast that now ships in 9 languages with consent-based voice preservation. Each one surfaced different failure modes, and each one taught us what actually matters at scale.

We also ship faster now because our delivery process is Agent-Engineered: Claude Sonnet 4.6 pair-programs our senior engineers on every story, cutting our time-to-first-production-deploy by 30–45% across recent projects. Accessibility work is especially well-suited to this because it’s a long catalog of small, high-certainty changes (alt text, ARIA, keyboard nav, focus management) where LLM-assisted refactoring shines.

Scoping a podcast accessibility rollout?

We’ll audit your ingest pipeline, transcript delivery, and web player against EAA / ADA Title II / WCAG 2.2 and return a written teardown with priorities.

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What “podcast accessibility” actually means in 2026

Accessibility is not one feature. It’s a stack of eight user-visible capabilities and three invisible delivery capabilities, all of which have to be right for the product to clear WCAG 2.2 AA and EAA baseline conformance.

Visible to the listener: synchronized transcripts, chapter markers, variable-speed playback (0.25× to 3×), translated transcripts, dubbed audio, episode summaries and key-takeaway extraction, search within an episode, search across the catalogue.

Visible to the assistive-tech user: screen-reader compatible web player, keyboard-only navigation, font-size and contrast controls, focus management, captions for video podcasts, audio descriptions for visual-only segments.

Invisible to both but required: the Podcasting 2.0 namespace in the RSS feed, a structured transcript format (WebVTT or SRT plus JSON for semantic search), and a delivery layer (CDN-hosted transcript files, embedded RSS references) that apps like Fountain, Podverse, Apple Podcasts, and Overcast can consume.

Market: the numbers driving the category

MetricValueSource
Global podcast market (2026)$39.63 BGrand View Research
US podcast ad spend (2026)$3 B+Edison Research Infinite Dial 2026
US monthly podcast listeners (12+)165 M (55%)Edison Research
Apple Podcasts auto-transcripts issued125 M episodes, 13 languagesApple Newsroom 2025
Podcasters deploying AI transcription~70%Industry surveys 2026
Adults in US with hearing trouble~37 MCDC / NIDCD
Weekly podcast listeners with disability19% (vs. 25% avg); vision-disabled 33%Ofcom 2025
SEO lift from transcribed episodes+6.68% rank, +16% backlinksMoz, 2025–2026 studies

The market read: accessibility isn’t a niche feature. Vision-impaired users over-index on podcast consumption by ~30% above the population average, and the SEO lift from full transcripts alone often pays back the accessibility stack’s annual cost in new organic traffic. Combine that with EAA enforcement (fines up to €1 M per infraction) and the question stops being “should we” and becomes “how fast.”

The four-layer reference stack

LayerJob2026 representative tools
1. Ingest + ASRTranscribe speech to word-level timestampsDeepgram Nova-3, AssemblyAI Universal-2, OpenAI Whisper v3 / v3-turbo, NVIDIA Parakeet TDT 1.1B, Gladia, Speechmatics
2. EnrichmentDiarization, chapters, summary, translation, dubbingpyannote 3.1, NVIDIA NeMo, WhisperX, ElevenLabs dubbing (32 langs), Respeecher, DeepL, Google Translate, Claude Sonnet 4.6 for chapter + summary
3. DeliveryServe transcripts + metadata to apps + web playerCloudflare R2, Backblaze B2, S3, Podcasting 2.0 RSS namespace, WebVTT / SRT, HLS for video podcasts
4. Web player + searchRender accessible UI + enable semantic navigationPinecone / Weaviate / Qdrant for vector search, WCAG 2.2-compliant React player, ARIA live regions

Our opinion

Teams over-invest in ASR accuracy (+1% WER at +100% cost) and under-invest in the web player. A 92%-accuracy transcript rendered in a WCAG-compliant synchronized reader beats a 98%-accuracy transcript hidden behind a broken keyboard-nav experience. Spend the first budget on the player, then on the pipeline.

ASR landscape — which model for which podcast

ModelLab WERReal-world podcast WERStrengths
Deepgram Nova-35.26%12–15%Best streaming latency (54.3% reduction vs. peers); strong on accents and code-switching
AssemblyAI Universal-214.5%15–18%+21% alphanumeric accuracy; cheapest at scale ($0.0025/min)
OpenAI Whisper v37.4%13–20%Best multilingual coverage (99 langs); open-weight, self-hostable
NVIDIA Parakeet TDT 1.1B6.2%12–16%English only; best per-GPU throughput on H100 / H200
Whisper.cpp (tiny / base)12–14%18–22%On-device / edge; zero cloud cost, zero latency for privacy-first apps

The honest rule: for a VOD podcast pipeline the choice is almost always Deepgram Nova-3 (quality + latency + accents) or AssemblyAI Universal-2 (cost at scale, strong LeMUR integration for chapter + summary). Whisper v3 remains the right answer only if self-hosting is mandated by legal (HIPAA on-prem, for example) or if the language is outside the big-3’s strongest tier.

Diarization, translation, dubbing — the enrichment layer

Diarization (“who spoke when”) is the second-hardest problem after ASR. pyannote 3.1 lands at 11.2% DER on VoxConverse (easy) and 20.2% on DIHARD III (hard, multi-speaker, overlapping). Deepgram and AssemblyAI ship tightly-integrated diarization that handles most two- to four-speaker conversations well; above five speakers, error rates climb sharply. If your podcast is a panel format, budget for manual correction of speaker labels on roughly 10% of turns.

Translation. DeepL and Google Cloud Translate handle major European and East Asian languages with BLEU scores above 40 on formal speech. Colloquial and idiomatic speech drops BLEU by 15–20 points. For translated transcripts destined for the WCAG-compliant web player this is acceptable; for dubbed audio you need native speakers to review.

Dubbing. ElevenLabs now supports 32 languages with emotional-tone and timing preservation; Respeecher and Resemble AI offer consent-based voice preservation (the speaker’s own voice in a different language). Consent is a hard legal requirement: under the EU AI Act Article 50 transparency clause, dubbed content that uses voice cloning must be labeled as AI-generated.

Chapter markers and summaries. Claude Sonnet 4.6 or Gemini 2.5 Pro with a structured-output prompt on top of the transcript produces a clean chapter list (title, start_ms, summary) and a 120-word episode abstract. Cost per episode: $0.10–0.30 for 1–2 hours of audio.

Podcasting 2.0: the delivery standard

The Podcasting 2.0 namespace is the RSS-level standard for delivering accessibility metadata. If you ship a podcast product in 2026 and you do not implement at minimum <podcast:transcript> and <podcast:chapters>, you are leaving accessibility capability on the table that Fountain, Podverse, Podcast Addict, Castamatic, and — as of March 2026 beta — Overcast already render natively.

Namespace tagPurposeBroad app support
<podcast:transcript>VTT, SRT, JSON, HTML transcript reference with language tagApple, Fountain, Podverse, Podcast Addict, Overcast (beta)
<podcast:chapters>JSON chapter file with start_time, title, optional imageMost Podcasting 2.0 apps, iOS 17.4+ Apple Podcasts
<podcast:person>Speaker metadata (name, role, image, link)Fountain, Podverse, Podcast Guru
<podcast:soundbite>Mark a highlight clip (start, duration, title)Fountain, Podverse
<podcast:alternateEnclosure>Audio description track, translated dub, alternate bitrateFountain, Podverse, custom players
<itunes:transcript>Apple’s parallel namespace, VTT / SRT onlyApple Podcasts only

Two practical points about platform support:

Apple Podcasts auto-generates transcripts (125 M episodes in 13 languages as of mid-2025) but accepts creator-provided VTT and SRT via the <itunes:transcript> or <podcast:transcript> tag; the creator version overrides the auto-generated one. Always ship your own transcript if quality matters.

Spotify still does not accept creator-provided transcripts via RSS as of April 2026 and auto-generates only for select shows. This is the single largest podcast-accessibility gap at the major-platform level; plan for it.

Compliance: what binds in 2026

FrameworkScopeKey 2026 requirement
European Accessibility Act (EAA)EU podcast platforms, streaming services, e-books, audiobooksEffective June 28, 2025. Fines up to €1 M per infraction; references WCAG 2.1 AA, EN 301 549
ADA Title II (DOJ April 2024 rule)US state + local government web, mobile, audio, video>50 k pop: April 24, 2026. <50 k: April 26, 2027. WCAG 2.1 AA
WCAG 2.2 (W3C Oct 2023 final)All web content, podcast web players9 new criteria since 2.1: focus-not-obscured, target size 24×24, dragging alternatives, consistent help
Section 508US federal agencies and vendorsAligns with WCAG 2.0 AA today, 2.2 AA review in progress
CVAA + FCC IP captionsVideo podcasts distributed over IPClosed captions required; quality standards on accuracy, synchronicity, completeness, placement
UK Equality Act + Public Sector RegsUK-registered platforms, public bodiesReasonable-adjustments duty, WCAG 2.1 AA for public-sector sites
Accessible Canada ActFederally regulated Canadian organizationsAccessibility-plan and progress-report obligations, escalating penalties since 2024
EU AI Act Article 50AI voice cloning, dubbed audio, synthetic speechLabeling obligation from August 2026: AI-generated audio must be disclosed

Compliance shortcut we use

Write a one-page Accessibility Conformance Report (ACR / VPAT 2.5) that maps your product against WCAG 2.2 AA, Section 508, and EN 301 549. Auditors read this document first. Ship it alongside the product — not in response to a complaint — and procurement teams in government and enterprise will approve faster. We template this in one afternoon; it saves weeks later.

Cost model: per-episode and per-catalog

Line itemPer 1 hour of audio
ASR (AssemblyAI Universal-2)$0.15
ASR (Deepgram Nova-3, pay-as-you-go)$0.46
ASR (AWS Transcribe, standard)$1.44 (down to $0.47 at 5 M min / mo)
Diarization (cloud-tier)+$0.05–0.10
Translation + dubbing (3 languages, ElevenLabs)$0.50–1.50
Chapter + summary via Claude / Gemini$0.10–0.30
CDN + storage (Cloudflare R2 / Backblaze B2)<$0.02
Total per hour of audio$0.80–$2.30

For a show producing 40 hours of audio per month, the all-in ingest-to-delivery cost of the full accessibility suite is $35–95 per month. For a network of 200 shows at the same cadence, $7 000–19 000 per month. This is consistently one of the cheapest compliance-driven investments a podcast platform makes.

Architecture: the pipeline we ship

Every podcast-accessibility system we’ve shipped maps to the same seven stages. If your team skips one, that’s where the audit finding will surface.

1. Ingest. New episode enclosure URL lands on an RSS feed; webhook or scheduled poller queues a job. Kafka, SQS, or a lightweight pub/sub (Redis Streams, NATS) handles the fan-out.

2. ASR. Batched call to Deepgram Nova-3 or AssemblyAI Universal-2 (or an on-prem Whisper worker if privacy-driven). Output: word-level JSON with timestamps, confidence, speaker channel hints.

3. Enrichment. pyannote diarization overlay, Claude Sonnet 4.6 chapter + summary extraction, optional DeepL / ElevenLabs translation and dubbing for each target language.

4. Transcript assembly. Merge ASR + diarization + translation into a canonical JSON, then emit WebVTT and SRT sidecar files. Store all three in R2 / B2 / S3 with versioned keys.

5. RSS enrichment. Update the RSS feed with <podcast:transcript>, <podcast:chapters>, and (for multi-language dubs) <podcast:alternateEnclosure> entries. Re-sign if using Podping or WebSub.

6. Semantic index. Chunk the transcript (60-second windows with 10-second overlap), embed with Gemini Embedding 2 or Qwen3-Embedding-8B, upsert to Pinecone / Weaviate / Qdrant. This powers in-episode search, cross-catalog discovery, and RAG for episode Q&A.

7. Web player. React + ARIA live regions render the synchronized transcript; WCAG 2.2 AA-compliant controls (24×24 target size, focus-not-obscured, keyboard nav). Test with NVDA, JAWS, and VoiceOver before ship.

Pipeline tip we’ve earned the hard way

Make the transcript-assembly stage (step 4) idempotent from day one. ASR providers reprocess old audio when they release a new model; diarization libraries bump accuracy between minor versions. Teams that treat the JSON transcript as the canonical artifact — with a version field and deterministic keys — can re-run any episode in seconds when a better model lands, instead of rebuilding the whole enrichment stack. This single decision is what lets us ship accessibility upgrades 3–4× faster than teams that bolt transcripts onto a legacy CMS.

Mini case: EdTech audio platform ships EAA-ready in 9 weeks

A Fora Soft client runs a European corporate-learning platform that delivers ~4 000 lectures per year as audio-first content. EAA went live June 28, 2025, and the client’s legal team gave us 12 weeks to be compliant, or cancel the EU rollout. We shipped in 9.

Stack we deployed:

  • ASR: Deepgram Nova-3 (accents, code-switching, streaming).
  • Diarization: Deepgram-integrated (2–3 speakers typical).
  • Translation: DeepL to 6 EU languages; AI summaries + chapters via Claude Sonnet 4.6.
  • Delivery: Cloudflare R2, Podcasting 2.0 RSS namespace, WebVTT + SRT.
  • Web player: new React component, WCAG 2.2 AA conformance, tested with NVDA and VoiceOver.
  • Semantic search: Pinecone serverless index over all ~6 000 hours of archival content.

Outcomes after 90 days in production:

  • EAA conformance audit passed first review; VPAT 2.5 signed by external auditor.
  • Episode-completion rate up 14% (CUPED-adjusted treatment cohort).
  • Organic search traffic from transcript pages added 38 000 monthly visits within 90 days.
  • Support tickets about “can I get a transcript” dropped 94%.
  • Total infrastructure cost: $2 400 / month at 4 000 lectures / year + 6-language translation.

5 pitfalls that kill podcast-accessibility projects

1. Treating the transcript as the deliverable. The transcript is raw material. The deliverable is the synchronized, searchable, accessible reader in your web player and in third-party apps. Teams that stop at the JSON file fail audits.

2. Under-investing in the web player’s accessibility. ARIA live regions wrong, focus management broken, color contrast below 4.5:1, target sizes below 24×24 — any of those will fail WCAG 2.2. Test with a real screen reader (NVDA, JAWS, VoiceOver) every sprint, not just at release.

3. Skipping consent for voice cloning. ElevenLabs, Respeecher, Resemble AI all require verifiable consent for voice reuse. EU AI Act Article 50 (effective August 2026) requires disclosure that dubbed audio is AI-generated. Running a cloned voice in production without documented consent + disclosure is a straight-line fine.

4. Relying on platform auto-transcripts. Apple auto-generates but lets creators override; Spotify still doesn’t accept creator uploads via RSS as of April 2026. If you rely on auto-generation you have no control over quality, language coverage, or delivery timing. Ship your own.

5. Ignoring the RSS-propagation delay. Aggregators re-poll feeds on 15-minute to 24-hour cycles. If your pipeline updates the RSS after the episode goes live, accessibility features can lag by hours. Serve transcripts ready-to-go from the publish event, not from a post-publish job.

Budget heuristic we use

For a podcast platform with 100–500 active shows, realistic year-one budget for a full accessibility stack: $180 k–$340 k engineering, $2 k–$8 k / month runtime, $15 k external accessibility audit. Book a 30-minute call and we’ll benchmark a vendor quote you’re evaluating against that range.

KPIs: what to measure

Accessibility quality: transcript WER on a sampled test set, diarization DER, caption accuracy percentage (WCAG-recommended ≥95%), WCAG 2.2 AA conformance on the web player, axe-core automated audit score, NVDA / VoiceOver manual test pass rate.

User impact: episode-completion-rate lift, transcript-view rate, transcript-to-search click-through, time spent per episode, catalog-wide search usage, per-language engagement for translated content.

Compliance + ops: days-from-publish-to-transcript-live, percentage of episodes with transcript + chapters + summary, number of disability-related support tickets, results of quarterly external accessibility audit.

When NOT to build this in-house

We recommend against a full in-house build in three cases:

  • Fewer than ~50 episodes per month. Managed services (Podcastle, Descript, Castos, Buzzsprout + integrations) cover the use case for under $200 / month with no engineering overhead.
  • No web-player team. If you don’t own your player, 40% of the WCAG 2.2 AA criteria are out of your control. Fix that first, then add accessibility to it.
  • No semantic-search ambition. If you never plan to search inside or across episodes, a third-party transcription-plus-delivery SaaS like Podscribe is cheaper than a pipeline.

Decision framework — pick your stack in six questions

  1. Am I subject to EAA, ADA Title II >50 k, or a federal 508 procurement? If yes, the answer is a full pipeline + VPAT, not a SaaS wrapper.
  2. Is latency important (live captions, real-time translation)? If yes, Deepgram Nova-3 streaming. Otherwise batch on AssemblyAI for half the cost.
  3. Do I need multilingual (transcripts + dubs)? If yes, DeepL + ElevenLabs. Budget the consent + Article 50 disclosure workflow.
  4. Does content contain jargon, accents, code-switching? If yes, expect real-world WER 12–20% and plan human-in-loop correction on top 1% of listened content.
  5. Do I need search inside and across episodes? If yes, index embeddings in Pinecone or Weaviate from day one. Retrofitting costs 3×.
  6. Do I own my web player? If no, accept that you will fail half the WCAG criteria until you do. Prioritize that refactor.

Want us to run this framework with you?

In 30 minutes we’ll walk through your current player, ingest, and RSS output and return a written EAA / ADA Title II readiness teardown.

Book the call →

Integration playbook: the 10–14-week path

WeeksPhaseDeliverables
1–2Discovery + VPAT / ACR draftWCAG 2.2 gap analysis, EAA scope, player audit, VPAT 2.5 skeleton
3–4Pipeline v1Deepgram / AssemblyAI integration, storage, transcript schema, RSS enrichment
5–7Player refactorWCAG 2.2 AA web player, synchronized transcript, keyboard nav, ARIA live, font + contrast controls
8–9Enrichment + searchChapters, summaries, translation, dubbing, semantic index in Pinecone / Weaviate
10–11Audit + remediationExternal WCAG 2.2 audit, NVDA / JAWS / VoiceOver testing, remediation sprint
12–14Launch + monitoringSigned VPAT, accessibility statement page, monitoring + alerting, retrain cadence, team training

Where podcast accessibility is heading in 2026–2027

On-device ASR. NVIDIA NIM, AMD Ryzen AI, Whisper.cpp, and Apple’s on-device models are pulling transcription onto the listener’s device for privacy-sensitive verticals. Expect “private podcast” apps (therapy, corporate training, journalism sources) where transcripts never touch the cloud.

Real-time dubbed livestreams. ElevenLabs and HeyGen already dub on-demand with sub-second latency in studio; 2026–2027 will see it plugged into live-streaming protocols (LL-HLS, WebRTC) for simultaneous multi-language podcast livestreams.

Semantic discovery. Transcript-indexed vector search turns podcast catalogs from “browse by show” into “ask a question, get a clip list.” Snipd, Podscribe, and independent players are already here; platforms that hold listener data will follow.

Audio-description automation for video podcasts. Twelve Labs Marengo 3.0, Gemini 2.5 Pro, and Claude 4.6 can now draft audio descriptions from video frames; a human reviewer per hour of content keeps cost reasonable, and WCAG 2.2 success criterion 1.2.5 gets easier.

FAQ

Do I need a transcript if Apple already auto-generates one?

Yes. Apple’s auto-transcripts are a baseline, not a ceiling; they don’t render in most third-party apps, don’t cover all languages, and can’t be corrected by you. Creator-provided transcripts via <podcast:transcript> override Apple’s and render everywhere Podcasting 2.0 is supported.

VTT or SRT?

Ship both. WebVTT is web-native and CSS-styleable; SRT has the broadest platform and LMS compatibility. Generating SRT from VTT is trivial, and both cost you a few kilobytes per episode.

What WER is “good enough”?

Under 10% on a representative sample is a strong 2026 target. WCAG and most regulators prefer to speak in terms of “effective equivalent to the spoken content”; in practice, auditors accept captions at ≥95% word accuracy on a sampled review.

Can I use voice cloning to dub episodes into other languages?

Only with verifiable consent from the speaker, and under EU AI Act Article 50 you must disclose the audio is AI-generated once the provision is in force (August 2026). Use ElevenLabs Professional Voice Cloning, Respeecher, or Resemble AI with documented consent records.

How do I handle multi-speaker panels with overlapping speech?

Use a diarization layer trained on multi-party audio (pyannote 3.1 on DIHARD, or Deepgram / AssemblyAI’s integrated diarization) and expect to correct ~10% of speaker labels manually on panels of 4+. Budget that review step into your workflow.

Do I need to re-transcribe my entire back catalog?

Not all of it, but prioritize the top 20% by listens (usually 80% of engagement) and any episode that still actively sells ads or appears in search. Back-catalog transcription averages $0.15–0.46 per hour at bulk rates; the SEO payoff often justifies the full sweep.

How long until transcript changes propagate to apps?

RSS aggregators poll on 15-minute to 24-hour cycles. Using Podping (WebSub) reduces this to minutes for participating apps. Otherwise plan for same-day propagation on most clients.

Is Spotify support improving?

Spotify announced in late 2024 that creator-controlled transcripts were on the roadmap. As of April 2026 there is no public API for uploading them via RSS. Plan your product to serve transcripts on your own web player and via Apple / Fountain / Podverse in the meantime.

Language

AI simultaneous interpretation

The live-audio cousin of podcast translation — same ASR stack, sub-second latency.

Video Infra

AI streaming platform playbook

CDN, DRM, CMAF, and where captions and transcripts plug in.

Accessibility

AI accessibility in UI / UX design

The WCAG 2.2 design playbook that wraps around the podcast-specific stack.

Voice

Voice-activated mobile apps

The mobile-client side: voice input and voice feedback paired with accessible audio.

Summing up

Podcast accessibility in 2026 is a four-layer infrastructure problem: ingest and transcribe with Deepgram Nova-3 or AssemblyAI Universal-2, enrich with diarization and translation and AI chapters, deliver through the Podcasting 2.0 namespace, and render in a WCAG 2.2 AA web player that holds up under NVDA and VoiceOver. Teams that do this ship EAA / ADA Title II compliant products, win +15% completion rate, +6.68% search ranking, +16% backlinks, and reach the 33% of vision-disabled listeners who over-index on podcast consumption.

Fora Soft has been shipping audio and video platforms for 20 years, and our Agent-Engineered delivery compresses the full accessibility rollout into 10–14 weeks for most podcast products. If you’re scoping EAA or ADA Title II readiness this fiscal year, we’d like to be on the short list.

Ready to scope podcast accessibility?

30-minute call, written teardown of your current stack afterwards, no-obligation pricing.

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