---
name: speech-to-text-models-use
title: Using a model for speech recognition
description: You use the `model` parameter of a speech recognition request to indicate the model that is to be used with the request. You can specify a large speech model, previous- or next-generation model with the parameter.
last-updated: 2025-02-17
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/speech-to-text?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

# Using a model for speech recognition
{: #models-use}

You use the `model` parameter of a speech recognition request to indicate the model that is to be used with the request. You can specify a large speech model, previous- or next-generation model with the parameter.
{: shortdesc}

For more information about the models that are available for speech recognition, see

-   [Previous-generation languages and models](https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-models&format=markdown)
-   [Next-generation languages and models](https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-models-ng&format=markdown)
-   [Large speech languages and models](https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-models-large-speech-languages&format=markdown)

## Specify a previous-generation model example
{: #models-pg-specify-example}

The following example HTTP request uses the previous-generation model `en-US_NarrowbandModel` for speech recognition:

[IBM Cloud]{: tag-ibm-cloud}

```sh
curl -X POST -u "apikey:{apikey}" \
--header "Content-Type: audio/flac" \
--data-binary @{path}audio-file.flac \
"{url}/v1/recognize?model=en-US_NarrowbandModel"
```
{: pre}

[IBM Cloud Pak for Data]{: tag-cp4d} [IBM Software Hub]{: tag-teal}

```sh
curl -X POST \
--header "Authorization: Bearer {token}" \
--header "Content-Type: audio/flac" \
--data-binary @{path}audio-file.flac \
"{url}/v1/recognize?model=en-US_NarrowbandModel"
```
{: pre}

## Specify a next-generation model example
{: #models-ng-specify-example}

The following example HTTP request uses the next-generation `en-US_Telephony` model for speech recognition:

[IBM Cloud]{: tag-ibm-cloud}

```sh
curl -X POST -u "apikey:{apikey}" \
--header "Content-Type: audio/wav" \
--data-binary @{path}audio-file.wav \
"{url}/v1/recognize?model=en-US_Telephony"
```
{: pre}

[IBM Cloud Pak for Data]{: tag-cp4d} [IBM Software Hub]{: tag-teal}

```sh
curl -X POST \
--header "Authorization: Bearer {token}" \
--header "Content-Type: audio/wav" \
--data-binary @{path}audio-file.wav \
"{url}/v1/recognize?model=en-US_Telephony"
```
{: pre}

## Specify a large speech model example
{: #models-lsm-specify-example}

The following example HTTP request uses the large speech model `en-US` for speech recognition:

[IBM Cloud]{: tag-ibm-cloud}

```sh
curl -X POST -u "apikey:{apikey}" \
--header "Content-Type: audio/wav" \
--data-binary @{path}audio-file.wav \
"{url}/v1/recognize?model=en-US"
```
{: pre}

[IBM Cloud Pak for Data]{: tag-cp4d} [IBM Software Hub]{: tag-teal}

```sh
curl -X POST \
--header "Authorization: Bearer {token}" \
--header "Content-Type: audio/wav" \
--data-binary @{path}audio-file.wav \
"{url}/v1/recognize?model=en-US"
```
{: pre}

## Using the default model
{: #models-use-default}

If you omit the `model` parameter from a speech recognition request, the service uses the US English `en-US_BroadbandModel` by default. This default applies to all speech recognition requests.

[IBM Cloud Pak for Data]{: tag-cp4d} [IBM Software Hub]{: tag-teal} If you do not install the `en-US_BroadbandModel`, it cannot serve as the default model. In this case, you must either

-   Use the `model` parameter to pass the model that is to be used with each request.
-   Specify a new default model for your installation of Speech to Text for IBM Cloud Pak for Data by using the `defaultSTTModel` property in the Speech services custom resource. For more information, see  [Installing Watson Speech to Text](https://www.ibm.com/docs/en/cloud-paks/cp-data/5.0.x?topic=services-installing){: external}.