Intraoral voice recording-towards a new smartphone-based method for vocal rehabilitation.

After laryngectomy, a new voice is needed. We present the first steps in the development of a smartphone-based method. A microphone is placed in the mouth to record the pseudo-whispering voice of laryngectomized patients. This recording is analyzed by voice recognition software followed by voice synthesis. Eventually, this will be performed on a smartphone. We placed a microphone at 10 different places inside and outside the mouth (two in front of the mouth (at 2 and 20 cm), five on the palate and three on the lower jaw) and made voice recordings in eight healthy men. These recordings were analyzed by voice recognition software. The text generated by the software was compared with the original text. Over all positions, the correct detection of words recorded in the mouth was 19.3% vs. 75.2% (p = 0.01) outside the mouth. In the mouth, recording taken on the maxilla (22.8%) was much better than on the mandible (13.5%) (p = 0.01). The optimum position for a microphone on the maxilla was at the highest point of the palate with 31.9% correct word identification there (p = 0.028). Further investigations have to be undertaken with forthcoming development of smartphone processing power and with development of a smartphone-based voice recognition application.