Speech AI designed for children’s voices

We build technology that understands children’s voices better and can explain the evidence behind each result.

Internal validation7.05%

Child speech character error rate: 50 sentences from one held-out speaker, with no training overlap

Kaffol AI

From a child’s response to a report

We go beyond turning speech into text. The design considers age in months, the assessment items, and evaluation rules so that the evidence behind report statements can be reviewed.

  1. 01Child’s response

    Child speech and behavior input

    Children’s own responses captured through camera, microphone, and touch

  2. 02Speech recognition

    Service speech recognition

    The service transcribes children’s speech with OpenAI gpt-4o-mini-transcribe.

  3. 03Reviewing the evidence

    Interpretation linked to evidence

    Completed tasks, the child’s actual responses, and scoring criteria for each assessment

  4. 04Explaining results

    A clear, readable report

    Describing current observations and next conversations based on actual responses

Internal validation results

Compared using the same child speech samples

We compared the character error rate (CER) of ASR with our own LoRA on the same internal samples. A lower value means a closer match to the original text.

Evaluation conditions50 sentences from one held-out speaker, with no training overlap

This small internal benchmark examines the effect of LoRA on children’s speech. It does not demonstrate superior performance across general use cases.

Character error rateLower is more accurate
Character error rates by model on the same internal child speech samples
ModelCharacter error rate
Kaffol AI ASR7.05%
Qwen3-ASR 1.7B base8.89%
OpenAI gpt-transcribe9.56%

How we describe our technology

We distinguish current work from ongoing research.

Current work

Speech recognition in the service

The service uses OpenAI gpt-4o-mini-transcribe for speech transcription. Our Qwen-based ASR remains in research and is not used for service transcription or as a fallback.

Research

A small adapter for children’s speech

We are studying adaptation to children’s speech with an approximately 25 MB LoRA adapter that trains the text decoder while keeping the speech encoder fixed.

Roadmap

Exploring privacy through local AI

As field validation and manufacturing preparation progress, we are exploring local and on-device approaches that process children’s data closer to the device.

In preparation01

Research-based statistical analysis and papers

We are preparing statistical analyses and research papers based on item research. We do not present ongoing research as completed.

R&D02

Two patent applications relating to local AI

We have filed two patent applications relating to local AI. They are identified as applications, not granted patents.

Research with us

We are looking for partners in child speech research and field pilots.

Discuss technology and research collaboration