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Multilingual voice: Urdu, Arabic and English

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Multilingual voice: Urdu, Arabic and English

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Chapter 1 of 13

Multilingual voice

  • Code-switching is normal
  • Urdu, Arabic, English
  • Scripts, numbers, dates, register
  • Evaluate per language

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Chapters

Multilingual is the default in our markets

In Pakistan, the UAE and Saudi Arabia, many callers switch languages mid-sentence. A Karachi customer might say "Mera order abhi tak nahi aaya, can you check the status?" A Dubai caller might mix Gulf Arabic and English. A Riyadh caller might speak Najdi Arabic, while your content is in Modern Standard Arabic. Designing for one language at a time fails these callers.

Challenges by layer

LayerChallengeMitigation
ASRDialects (Gulf, Najdi, Egyptian, Levantine; Urdu regional accents), code-switching, names, numbersTest ASR on real recordings from your callers; choose models strong in your dialects; add keyword/vocabulary hints where supported; allow keypad input for numbers
Language detectionShort utterances ("ok", "yes", "haan") are ambiguousDetect on longer turns; confirm language switch; avoid flip-flopping (some platforms can restrict switching to the start of the call)
LLMUnderstanding mixed input; responding in the right registerInstruct "reply in the language the caller uses"; provide examples in each language; specify MSA vs dialect style
TTSVoice quality in each language; pronunciation of names, brands, English words inside Urdu or Arabic sentencesPick voices tested in each language; use multilingual models; pronunciation dictionaries; consider separate voices per language
ContentKnowledge base only in EnglishMaintain approved translations; retrieve in the caller's language or translate carefully with review

Script and formatting issues

  • Urdu is written in Nastaliq-style Perso-Arabic script, right to left; Roman Urdu (Urdu in Latin letters) is common in messages. ASR may output either; decide what your downstream systems expect.
  • Arabic numerals: Western digits (0-9) vs Eastern Arabic digits. Normalize before tools.
  • Dates: callers may reference the Hijri calendar, especially around Ramadan and Eid. Resolve carefully and confirm Gregorian dates.
  • Names: transliteration varies (Mohammed, Muhammad, Mohamed). Match flexibly in CRM lookups.

Register and politeness

  • Arabic: many businesses use a friendly, lightly formal Gulf style for spoken service in the UAE and KSA; MSA can sound stiff on the phone but is safer for legal statements. Decide deliberately and test with local listeners.
  • Urdu: respectful forms ("aap") are standard for customers; English technical terms (OTP, account, order) are often clearer than pure Urdu equivalents.
  • Greetings matter: "Assalam o alaikum" / "As-salamu alaykum" and appropriate responses.

Code-switching strategy

Options:

  1. Mirror: reply in the caller's dominant language, allowing common English terms. Most natural.
  2. Ask once: "Would you prefer Urdu or English?" at the start. Simple, slightly robotic.
  3. Primary language with switching: default to Arabic in KSA, switch to English on detection.

Some platforms offer specific modes for mixed-language speech (for example handling of Hindi-English mixing) and language detection system tools. Test what works on your callers' speech.

AI disclosure, recording notices and key terms should be delivered in the caller's language. Keep approved translations of mandatory statements, reviewed by native speakers, and do not let the LLM improvise them.

Worked example: a Pakistani telecom's bill-inquiry agent

  • Default greeting in Urdu with an English option: "Assalam o alaikum, main [brand] ki AI assistant hoon. Aap Urdu ya English mein baat kar sakte hain."
  • ASR tested on 200 real call snippets from Karachi, Lahore and Peshawar; the team chose the model with the lowest error on numbers and names and enabled keypad entry for account numbers.
  • Prompt allows English terms ("bill", "package", "data") inside Urdu replies.
  • TTS: one voice strong in both languages; pronunciation dictionary for package names.
  • Evaluation: separate success metrics per language to detect hidden gaps.

Hands-on: a multilingual evaluation set

id,language,dialect,utterance,expected_intent,expected_language_reply,notes
u01,ur,karachi,"Mera bill zyada aaya hai, check kar dein",bill_inquiry,ur,
u02,ur-en,lahore,"Mujhe apna data package change karna hai please",package_change,ur,code-switch
u03,ar,gulf,"أبغى أغير موعدي لبكرة العصر",reschedule,ar,tomorrow afternoon
u04,ar,najdi,"وش أوقات الدوام يوم الجمعة؟",hours_query,ar,
u05,en,uae,"Hi, can I move my appointment to Thursday?",reschedule,en,
u06,ar-en,gulf,"Hi, أبي أحجز appointment للأسنان",book,ar,code-switch
u07,ur,peshawar,"Account number hai 0 3 4 5... 6 7 8... 9 0 1 2",identify,ur,digits with pauses

Record these (or real, consented samples) as audio, run them through your agent, and score intent accuracy, reply language and task success per language and dialect.

Pitfalls

  • Testing only in English and assuming other languages "just work".
  • Letting the LLM translate mandatory legal statements on the fly.
  • Reporting a single overall success rate that hides a failing language.

Key takeaways

  • Code-switched Urdu-English and Arabic-English speech is normal in PK, UAE and KSA; design and test for it explicitly.
  • Test ASR on real dialect recordings, allow keypad input for numbers, and avoid language flip-flopping on short utterances.
  • Normalize scripts and digits, confirm Hijri-referenced dates, and match transliterated names flexibly.
  • Use approved, native-reviewed translations for disclosures and legal statements; report success per language and dialect.

Check your understanding

Quick questions to lock in the lesson. They don’t count towards your certificate.

  1. A Karachi caller says 'Mera order abhi tak nahi aaya, can you check?' Which reply strategy is usually most natural?
  2. Why should the AI disclosure and recording notice use pre-approved translations?
  3. Overall task success is 88%, but Arabic calls succeed far less often than English. What does this show?

Put it into practice

Adapt the multilingual evaluation set to your callers. Record at least five utterances per language or dialect, run them through your agent, and report success per language. Fix the weakest language first.

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