When phones became smartphones, they sprouted a new feature: sizable screens. Consumer Cellular, a nationwide wireless phone company that offers service to AARP members, is taking advantage of that fact to provide a useful service: closed captions for phone conversations.Mobile Captions Service lets the deaf and hard of hearing see a typed transcript of a phone conversation in real time as it’s going on. The captions are created by live operators on the fly based on a technology called Voice Carry Over (VCO) and are provided through a partnership with Hamilton Relay Service; the service is currently available on one phone, the Nokia E5 and is available in eight states and the District of Columbia.