dkpdf_remove_shortcodes_bytag_maintain_text.php

<?php
// removes specific shortcode in PDF
function dkpdf_remove_shortcodes_bytag( $content ) {

	$pdf = get_query_var( 'pdf' );

	if( $pdf ) {
		remove_shortcode( 'responsivevoice' );	
		$content = str_replace('[responsivevoice voice="Danish Female" buttontext="Læs opgaven"]', '', $content);
		$content = str_replace('[/responsivevoice]', '', $content);
	}

	return $content;

}
add_filter( 'the_content', 'dkpdf_remove_shortcodes_bytag');