The objective of this study is to evaluate pre- and intraoperative voice quality, the degree of vocal fold closure and the Maximum Phonation Time (MPT), first determined after temporary APrevent® VOIS implantation and then after permanent existing product implantation.

Inclusion Criteria:

• Male and female patients between 18 and 80 years
• Diagnosed with permanent UVFP and insufficient glottal closure and planned type I thyroplasty with conventional implant
• Ability to co-operate with the investigator and to comply with the requirements of the entire study

Exclusion Criteria:

• Any other significant disease or disorder which, in the opinion of the investigator, may either put the participant at risk because of participation in the clinical investigation may influence the result of the clinical investigation, or the participant's ability to participate in the clinical investigation
• Scheduled elective surgery or other procedures requiring general anaesthesia during clinical investigation
• Had medialization thyroplasty before
• Had injection medialization laryngoplasty in the past two years.
• Presence of structural vocal fold lesions such as polyp or nodules
• Status post total cordectomy
• Previous laryngeal framework surgery (any type of thyroplasty, arytenoid adduction)
• Significant non-laryngeal speech abnormality (severe dysarthria determined by a panel of trained speech therapists)
• Severe coagulopathy