The vast majority of employers would not benefits from recording employees with transcription systems. The cost to records the employees and then store all of this data would be far to high. Some employees in some situations should be recorded, such as in legal proceedings, but that takes place already in courtrooms and law offices.
I do not agree that all conversations within a company need to be transcribed. I can understand the technology being used to record calls from customers to improve upon a company's customer service. But recording conversations in a break room or in a hallway is taking it to far. What would a company hope to gain from such an invasion of privacy?
It is a violation of privacy to record their employees using transcription systems. Some could argue that companies have the right to do it as long as the employee signs a contract and understands they will be recorded but I don't think they should start doing it. People have a right to have all of their conversations be as private as they want them to be. Not to have some stranger listen in when their #1 customer starts asking about their kids. I wouldn't want strangers knowing those things about me or my family. It will start making the business world even more impersonal than it is now.
It would make employees extremely uncomfortable to know that they were being watched every second of the day while they are at work. If a company doesn't give its employees a certain level of trust, the employees in turn will not trust the company. This does not lead to productive work.