Tutorial: Audio management and the cache
Level 2 – Lesson 5 of 8 – Understand and manage the audio cache for optimal performance.
Audio library controls how TTS output is generated, cached, and replayed. Without understanding caching, teams often think changes “didn’t apply” when they’re hearing old audio.
Understanding the audio cache
One-off utterances will not persist in cache by default.
Managing cached audio
Review cached utterances
Check the list of cached utterances:
- Greeting
- Transfer / handoff language
- SMS offer phrasing
- Closings and confirmations
Check your understanding
You updated your agent's greeting text and published the change, but callers still hear the old greeting. What is the most likely cause?
- The change wasn’t saved before publishing
- The old greeting is still cached – start a new call session to hear the updated audio
- The voice model doesn’t support greeting changes
- You need to re-select the agent voice first
Answer: The old greeting is still cached – start a new call session to hear the updated audio
Cached audio persists until refreshed. After any voice or phrasing change, start a new call session to confirm you’re hearing the updated audio, not a cached version.
Interaction style (response latency)
Interaction style controls how quickly the agent responds after detecting user speech. This directly affects interruption rate and perceived naturalness.
Turbo
Swift
Balanced
Precise
~400ms latency
Extremely fast, higher interruption risk.
Barge-in
What is barge-in?
Barge-in determines whether callers can interrupt the agent mid-speech.
When to use it
- Useful for Turbo mode
- Can feel chaotic if enabled without careful phrasing and latency tuning
Pronunciations
Ensure domain-specific terms are spoken clearly and correctly in Call.
Pronunciations are defined in the Pronunciations tab under Voice > Advanced settings and applied globally. They modify how text is converted to speech, without changing the underlying text.
When to use pronunciations
How pronunciations work
Matching is done using regular expressions. Replacements can be:
IPA
SSML
Regex capture groups
International Phonetic Alphabet
For precise pronunciation control
Examples
IPA correction
Regex: \bLouvre\b
Replacement: /ˈluːvrə/
Case sensitive: FALSE
Phone number formatting with pauses
Regex: (\d{3})[ -]?(\d{3})[ -]?(\d{4})
Replacement: \1 <break time="0.5s" /> \2 <break time="0.5s" /> \3
Best practices
Check your understanding
When does Agent Studio cache an audio utterance?
- After every conversation
- When the same utterance appears 5+ times in a single session
- When the same utterance is generated at least twice in a 24-hour window
- Only for greetings and sign-off phrases
Answer: When the same utterance is generated at least twice in a 24-hour window
One-off utterances don’t persist in cache by default. Repetition in the 24-hour window is what triggers caching.
Verification checklist
After any voice or phrasing change:
- Start a new call session
- Confirm you are hearing updated audio, not a cached version
- Validate that turn-taking still feels natural after changing latency or barge-in
- Mispronounced terms are corrected consistently
- Pauses improve comprehension rather than slowing the call excessively
Try it yourself
Challenge: Fix a mispronounced brand name
Your agent says “Hopper” but it is consistently pronounced incorrectly (sounds like “Hooper”). You also want phone numbers read back with a natural pause between each segment.
Write both pronunciation configurations:
- IPA correction for “Hopper”
- Phone number formatting with 0.5s pauses
Hint
For the IPA, write out what “Hopper” sounds like phonetically. For the phone number, use regex capture groups to split the digits and insert SSML <break> tags.
Example solution
Brand name correction:
- Regex:
\bHopper\b - Replacement:
/ˈhɒpər/ - Case sensitive: FALSE
Phone number with pauses:
- Regex:
(\d{3})[ -]?(\d{3})[ -]?(\d{4}) - Replacement:
\1 <break time="0.5s" /> \2 <break time="0.5s" /> \3
Check your understanding
You want the agent to respond as quickly as possible, even if it means a higher risk of interrupting users. Which interaction style should you choose?
- Balanced (~1600ms) – the default for most use cases
- Swift (~1200ms) – faster responses, lower interruption risk than Turbo
- Turbo (~400ms) – fastest response, highest interruption risk
- Precise (~2000ms) – most deliberate, fewest interruptions
Answer: Turbo (~400ms) – fastest response, highest interruption risk
Turbo has the lowest latency at ~400ms, making the agent respond almost immediately. The trade-off is a higher risk of cutting the user off mid-sentence. Use it with care and thorough call testing.