una/modules/base/general/template/attachment_sound.html

<div class="bx-base-general-attachment-sound">
    <div class="bx-base-general-attachment-sound-file-name bx-def-padding-sec bx-def-box-sizing">__file_name__</div>
    <div class="bx-base-general-attachment-sound-player">__player__</div>
</div>