Troubleshooting Unity VR audio and VAD issues

What do you need help with?

Question

Installation method

Unity Asset Store

Issue area

Hands-Free Conversation / VAD

Impact

Normal - something is not working as expected

Unity version

6000.0.59

Convai Unity SDK version

4.1.0

Target platform

Meta Quest

Where does it happen?

Both sample and custom scene

Short summary

Multiple issues related to Hands-Free Conversation, VAD, microphone muting, TTS playback, and language detection in Unity VR application.

What happened?

We are developing a VR educational application using Convai on Meta Quest and are experiencing several conversation-related issues that affect the overall user experience.

Issue 1 – Text response appears but voice never plays
Occasionally, the AI successfully generates a response, but only the text is displayed.

Observed behavior:
User speaks.
Convai processes the request successfully.
The text response appears immediately.
No voice response is played.
The conversation appears to complete successfully on the text side, but the corresponding TTS audio is missing.

Issue 2 – Long delay between text and voice
We frequently observe a noticeable delay between the appearance of the text response and the start of voice playback.

Observed behavior:
User finishes speaking.
AI text response appears quickly.
Voice playback starts several seconds later.

The delay is significant enough that users often assume the AI has stopped responding or that the response has failed.

Issue 3 – AI speech gets interrupted by minor environmental noise

The AI appears to be highly sensitive to background sounds while speaking.

Examples include:
People talking nearby
General room noise
Meta Quest microphone artifacts

These sounds often cause the AI to stop speaking or interrupt its response, even when the user is not intentionally interacting with the system.

What did you expect?

  1. Every AI text response should generate a corresponding voice response.
  2. Voice playback should begin immediately or with minimal delay after the text response is generated.
  3. Minor environmental sounds and background noise should not interrupt the AI while it is speaking.
    04.English conversations should consistently be recognized as English without unexpected language switching or mixed-language transcriptions.
    05.The conversation experience should remain stable and predictable in a typical Meta Quest classroom or training environment.

I checked the relevant documentation, resources, and similar forum posts before posting.

on

I confirm that I did not include API keys, tokens, passwords, secrets, private character data, private conversation logs, or customer data.

on

Hello,

Welcome to the Convai Developer Forum!

Could you please share your Character ID and the session IDs where these issues occurred?

Also, please make sure you are using the latest version of the Convai Unity SDK and test again. This will help us review the issue more accurately.

HI K3,

thank you so much for quick respond .. appreciated… My character ID : 8cc31d16-4d00-11f1-98f0-42010a7be02e , the issue was happing in alot of session so let me list those Ids .. session IDs :


13-06-2026
05:49:17 a156d978-3e48-46ab-b004-d0c8d830710a
12-06-2026 12:34:58 c5bbea2e-7b89-4301-b6f2-e620a91be3d1
12-06-2026 12:07:59 7c30eee2-c148-4b00-8571-ccf2ab561847
12-06-2026 11:10:09 bac556b3-d69d-4c2a-89ab-1f883c954044
12-06-2026 11:06:09 b5903875-b976-4027-b237-d8dc87b9a097
12-06-2026 10:26:06 40b92598-7c21-4774-80d7-8cc6ed02e6a7
12-06-2026 10:24:59 ccf70bc2-80b2-4108-8b9f-9bce52e3fc99
12-06-2026 10:19:09 14dfa3c6-c593-42e8-8952-05ed8cc9ffed
12-06-2026 10:10:37 3a48d041-8717-45c3-82cf-7b2bbaf5ad27
12-06-2026 10:07:53 dc01e9fd-b3db-49c0-b3ad-1c4eb2dd490e
12-06-2026 10:01:54 08bee77d-7c0b-451e-b88a-837906b209f1
12-06-2026 09:53:22 fac90e44-8c58-4585-ba3a-02b25ced3f36
12-06-2026 09:37:58 92c698ad-9ca3-4b50-8117-6953f03e7df2
12-06-2026 09:30:49 4e5ba738-31ef-40b3-98b0-7b7d77601c14
12-06-2026 09:23:12 c60fcceb-e75d-468c-b5d7-21f1f58ba285
12-06-2026 09:15:12 55a72d41-39ce-41c5-bee9-2859e0a10b99
12-06-2026 09:03:53 22ba66ea-ba5a-495d-9292-de505a26825f
12-06-2026 08:59:46 9413704b-309f-405f-933a-f6136b2b6a70
12-06-2026 08:46:49 e704562c-fe81-46ba-9b3e-152a35de302f
12-06-2026 08:40:46 13fce981-18bf-4b38-9939-0acbdc02a81f
12-06-2026 07:34:37 cb0e6664-e928-450c-ac2e-d2d0d50dea7d
12-06-2026 07:28:06 8b28e513-4762-4249-849a-57aec2ee25c0
12-06-2026 05:41:11 0149ed85-ebef-4605-8a85-31b3a2a6d1f0
11-06-2026 11:25:28 9d6f99da-0da5-4096-8e9e-33ec641ede57
11-06-2026 11:14:28 21597724-9d03-43ca-b6ce-072af205c254

Could you please test with gemini-3.5-flash and let us know if the issue still occurs?

It started working. Now it has stopped again. it is an unreliable system. We have been testing for months now, and the responses are unsatisfactory.

First, i tried Gemini 3.5 Flash as you had suggested. It worked for a few hours, although giving extrenely weird and long responses. At one point, it answered back that i cannot answer this question and i am tired of answering for the same question. Which AI does that?

After a few hours, it stopped working. Now I have tried with flash lite, openAI models and even claude, but it does not work. it answers only in text. When asked, it responds that it can only answer in text.

Could you please test the same character directly on convai.com and let us know if the issue still occurs there?

I checked on my side, but I’m not seeing this behavior, and we have not received similar reports from other users. It may be related to your project setup or implementation, so testing directly on convai.com will help us confirm whether the issue is with the character/backend or with the project integration.

I tried talking to the character on a laptop, which does not work. I tried on a mobile phone - which started working. For VR, it is showing weird respones. In a few VR headsets, it responds back via audio, whereas in a few VR headsets - it is only responding in text. We are using Meta Quest 3S.

Do you know to encounter this problem?

We are preparing an update that is expected to address this issue.

Once the update is released, I will let you know so you can test again.

So, does it mean you are working on an update to overcome VR working issue - working in a few VR headsets and not working in the remaining?

Also, any expected date for the update? We are unable to commit to this feature in our product mainly because of its unexpected behaviour

Yes, we are working on an update related to this issue.

The update is currently under review by the Unity Asset Store. Once it is approved, it will be published.

We expect it to be available within the next few days, depending on the Unity Asset Store review process.

Could you please update and try again?