A Prototype Low-Cost Pharyngeal Vibration Device for Voice Rehabilitation Following Laryngectomy

Laryngeal cancer disproportionately affects socioeconomically disadvantaged patients and its incidence is increasing in low-resource environments. Surgical ablation with laryngectomy results in loss of voice necessitating rehabilitation, for which the current devices are prohibitively expensive or difficult to repair. In this study, we developed a prototype phonation device with accessible and affordable electronic and mechanical components. Material and vibration wave properties were chosen after modelling a modified longitudinal wave equation. The device consists of a 3D-printed cylinder with a tip-mounted oscillating solenoid controlled by a timer circuit to propagate longitudinal waves to the neck. Speech intelligibility and volume were assessed on healthy volunteers by measuring the accuracy of words heard by a listener after a brief introduction to device technique. This was repeated with a commercial electrolarynx device for comparison. The mean accuracy of the word recorded was 0.956 (IQR 0.940 - 1.000) with an audible frequency of 57Hz to 138Hz. The device demonstrated listener accuracy statistically similar to commercial devices with phonation frequencies that in range of average human voice. The device was more affordable than commercial devices (under 35 USD compared to 600 USD) with common electronic components obtainable from international retailers. The results provide motivate for further development with the goal of open-source distribution of a blueprint to be manufactured remotely in in low-resource settings.