services/audiopolicy/config/hearing_aid_audio_policy_configuration.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Hearing aid Audio HAL Audio Policy Configuration file -->
<module name="hearing_aid" halVersion="2.0">
    <mixPorts>
        <mixPort name="hearing aid output" role="source">
            <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                     samplingRates="24000,16000"
                     channelMasks="AUDIO_CHANNEL_OUT_STEREO"/>
        </mixPort>
    </mixPorts>
    <devicePorts>
        <devicePort tagName="BT Hearing Aid Out" type="AUDIO_DEVICE_OUT_HEARING_AID" role="sink"/>
    </devicePorts>
    <routes>
        <route type="mix" sink="BT Hearing Aid Out" sources="hearing aid output"/>
    </routes>
</module>