Klaske van Sluis

20 2.1. Introduction Conclusions: Studies on speech outcomes after TL are flawed in design and represent weak levels of evidence. There is an urge for standardized measure- ment tools for evaluations of substitute voice speakers. TES is the favorable speech rehabilitation method according to acoustic and perceptual outcomes. All speaker groups after TL report a degree of voice handicap. Knowledge of caretakers and differences in health care and insurance systems play a role in the speech rehabilitation options that can be offered. 2.1 Introduction As a consequence of total laryngectomy (TL), patients lose their natural voice, making speech rehabilitation with a substitute sound source a major rehabili- tation goal. The three main rehabilitation options are esophageal speech (ES), tracheoesophageal speech (TES), and electrolarynx speech (ELS) [1]. ES and TES have in common that the substitute sound source is internal, i.e. the voice is produced in the pharyngoesophageal (PE) segment. ES is performed by administering air into the esophagus, which is subsequently expelled, caus- ing mucosal vibrations in the PE-segment. In TES, pulmonary air channeled through a voice prosthesis or tracheoesophageal (TE) fistula. The voice pros- thesis enables pulmonary air to enter the esophagus, and prevents esophageal content from entering the airway. In TES, pulmonary air is the driving force for the mucosal vibrations in the PE-segment. In ELS the substitute sound source is external: an electrolarynx is a sound producing, mostly handheld device, which can be placed against the neck or cheek [1]. Worldwide, no evidence-based consensus exists on which speech rehabilita- tion method is best for restoring oral communication. It is often assumed that for TL patients a better voice quality is associated with an improved quality of life [2, 3]. For evaluating speech rehabilitation outcomes, multidimensional assessment is recommended [4, 5]. This systematic review focuses on acoustic analysis, per- ceptual evaluation, and patient-reported outcomes (PROs) of the three substi- tute speech options. Acoustic voice analysis regularly includes pitch and am- plitude measurements [6]. However, standard acoustic voice analyses are not always sufficient to measure substitute voices, because speech originating in the vibrating PE-segment, ES and TES, is known to contain more noise components and less regularity than laryngeal voice [7]. Perceptual evaluations of the speech rehabilitation methods also require a well-thought-out approach because of the deviances in regularity compared to laryngeal voices [8, 9]. Most convenient for such evaluations of substitute voices are overall impression of voice quality and impression of speech intelligibility [8, 9]. Results of speech rehabilitation from a patient’s perspective are mostly evaluated by Quality of Life (QOL) questionnaires such as those of the European Organization for Research and Treatment of Cancer, Quality of Life Questionnaire (EORTC), the module for patients with head and neck cancer 35-item version (EORTC QLQ-H&N35)