M. van der Torn

Design and in vitro testing of a voice-producing element for laryngectomized patients.

A voice-producing element has been developed to improve speech quality after laryngectomy. The design process started with the formulation of a list of requirements. The lip principle has the best potential for fulfilling the requirements. A numerical model was made to find the optimal geometry of an element based on the lip principle. Extensive in vitro tests were performed to check all requirements. For this a test set-up with realistic acoustic and aerodynamic properties was developed. Results show that the protruding lip length dominates fundamental frequency, cross-sectional area dominates flow resistance and relation between flow and fundamental frequency. Most requirements have been fullfilled; both for males and females a potentially good functioning prototype could be selected. Clinical experiments will be performed to confirm the quality of the voice-producing prosthesis.

Alternative Voice After Laryngectomy Using a Sound-Producing Voice Prosthesis

Objective To improve the voice quality of female laryngectomees and/or laryngectomees with a hypotonic pharyngoesophageal (PE) segment by means of a pneumatic artificial source of voice incorporated in a regular tracheoesophageal (TE) shunt valve.

Female-pitched sound-producing voice prostheses - initial experimental and clinical results

Abstract In order to improve voice quality in female laryngectomees and/or laryngectomees with a hypotonic pharyngo-oesophageal segment, a sound-producing voice prosthesis was designed. The new source of voice consists of either one or two bent silicone lips which perform an oscillatory movement driven by the expired pulmonary air that flows along the outward-striking lips through the tracheo-oesophageal shunt valve. Four different prototypes of this pneumatic sound source were evaluated in vitro and in two female laryngectomees, testing the feasibility and characteristics of this new mechanism for alternative alaryngeal voice production. In vivo evaluation included acoustic analyses of both sustained vowels and read-aloud prose, videofluoroscopy, speech rate, and registration of tracheal phonatory pressure and vocal intensity. The mechanism proved feasible and did not result in unacceptable airflow resistance. The average pitch of voice increased and clarity improved in female laryngectomees. Pitch regulation of this prosthetic voice is possible with sufficient modulation to avoid monotony. The quality of voice attained through the sound-producing voice prostheses depends on a patient’s ability to let pulmonary air flow easily through the pharyngo-oesophageal segment without evoking the low-frequency mucosal vibrations that form the regular tracheo-oesophageal shunt voice. These initial experimental and clinical results provide directions for the future development of sound-producing voice prostheses. A single relatively long lip in a container with a rectangular lumen that hardly protrudes from the voice prosthesis may have the most promising characteristics.

Assessment of alaryngeal speech using a sound‐producing voice prosthesis in relation to sex and pharyngoesophageal segment tonicity

A pneumatic artificial sound source incorporated in a regular tracheoesophageal shunt valve may improve alaryngeal voice quality.

Analysis of failure of voice production by a sound-producing voice prosthesis

OBJECTIVE To analyse the cause of failing voice production by a sound-producing voice prosthesis (SPVP). METHODS The functioning of a prototype SPVP is described in a female laryngectomee before and after its sound-producing mechanism was impeded by tracheal phlegm. This assessment included: perceptual voice evaluation of read-aloud prose by an expert listener; inspection of the malfunctioning SPVP; and aero-acoustical in vivo registrations using a computer-based data acquisition system. RESULTS Sound-producing voice prosthesis speech is higher pitched, stronger, contains less aperiodic noise and requires a lower airflow rate than the patients regular tracheoesophageal (TE) shunt speech. Tracheal phlegm caused malfunction of the vibrating silicone lip of the SPVP by causing it to stick to its stainless steel container in an opened position, thereby reducing the SPVP to no more than a regular TE shunt valve from a functional point of view. Tracheal phonatory pressure and dynamic vocal intensity range were not affected by the functional status of the SPVP. CONCLUSIONS To exploit the advantages an SPVP could offer female laryngectomees with an atonic or severely hypotonic pharyngoesophageal segment, the sound-producing mechanism of the SPVP needs to be less vulnerable to tracheal phlegm.