On a rainy Monday morning in September, more than 200 people turned up at the Tobin Center for the Performing Arts to watch a special performance by Parsons Dance. The first indication that the show, which was designed specifically for those with sensitivity to light and sound, wasn’t a standard-issue offering might have been the program. Rather than the expected dancer biographies and descriptions of each piece of choreography, it offered a “social narrative,” a guide to everything the audience could expect to encounter. It began with the process to pick up tickets, explained what ushers do and talked about how to behave during the performance. Rather than the usual guidelines — stay in your seat, sit quietly, pay attention — this program was more flexible. It told visitors they should try to be quiet and also told them that it was OK to cover their ears if they found the goings-on to be too noisy. During the performance, lighting was simplified, and the sound was dialed down a bit. The performance marked the Tobin Center’s first offering for audiences with special needs, a program that education staffers there hope to expand in the future to include both touring productions and stagings by resident companies.