This number is not meant to be called by most people, as this is a specific line meant catering to telecommunications devices for the deaf. More than that, it's only meant to be used by TDD devices who are registered to people in the Commonwealth of Pennsylvania.
Should you try to call this number without one of these devices, the system automatically tells you to hang up and try a different number. If you're not using a TDD device at all, you're instead directed to dial 1-800-932-4600 for assistance. If you're using a TDD device, but are not located in Pennsylvania, you're told to call 717-412-5300. At this point, the system moves to a busy signal, which is all you'll get until you decide to hang up.
Given that roughly 10 million Americans are deaf or hard of hearing, it's nice to see that the Commonwealth of Pennsylvania has a phone number specifically dedicated to their needs. The Commonwealth has a total of four numbers for those who require assistance, offering two numbers for customers with TDD devices and two numbers for customers without. This system ensures that customers who are hard-of-hearing can always reach a number dedicated to them, reducing wait times.
The Commonwealth does put out this information where anyone can find it. On its website, it includes on official documents all four of its phone numbers and what they're used for. In my case, I'm not sure if the fact I wasn't using a TDD device or the fact I don't have a Pennsylvania area code triggered the system's busy signal. Either way, I wasn't allowed to move past the opening message.
If it's because that number only works with TDD devices, I think it's a good thing. Having a number that only operates with TDD devices ensures the customer service reps on the other end are familiar with these devices and can handle any calls.
On the other hand, if it's because it only works with Pennsylvania area codes, I don't think that's a good thing. Given that Pennsylvania is a large state with 15 area codes, this problem isn't as big as it might be in other states, but people are still moving around fairly frequently. Having a number for in-state residents and out-of-state callers is a good thing, but forcing bona fide residents of Pennsylvania to call another number simply because they never changed phones wouldn't be.
Obviously, I can only recommend calling this number if you're a resident of Pennsylvania and using a TDD device, as it won't work otherwise.