Oesophageal Speech Enhancement Using Kalman Filters

This paper presents an oesophageal speech enhancement algorithm. Such exceptionally special type of voice is due to the laryngectomy undergone by those persons with larynx cancer. An oesophageal voice has extremely low intelligibility. This works proposes a method to improve its quality, which consists of stabilizing the poles of the transfer function of vocal tract model. With this aim, a Kalman filtering technique has been applied. When using this efficient speech enhancement procedure, the speech signal is usually modelled as an autoregressive (AR) process and represented in the state-space domain. The final speech improvement has been measured with the help of MDVP tools and the HNR parameter.