Case study: Experimental study on optimum level of synthetic speech simulating Lombard effect

The Lombard effect is an acoustic effect associated with human speech in noisy environments. By simulating the Lombard effect in synthetic speech, the intelligibil- ity of synthetic speech in noisy environments is improved. However, it is known that human speech characterized by the Lombard effect increases annoyance in addition to intelligibility. Therefore, the influence of the Lombard effect on synthetic speech in a noisy environment was examined in detail, considering not only intelligibility but also other criteria. It was found that the suitability of speech reproduction in- creased upon using the Lombard effect in a noisy environment. By simulating the Lombard effect in synthetic speech, the intelligibility of synthetic speech in noisy environments is improved. However, it is known that human speech characterized by the Lombard effect increases annoyance in addition to intelligibility. Therefore, the influence of the Lombard effect on synthetic speech in a noisy environment was examined in detail, considering not only intelligibility but also other criteria. It was found that the suitability of speech reproduction increased upon using the Lombard effect in a noisy environment.