I was watching a piece on 60 Minutes the other day about the MIT Media lab and one invention being worked on was the use of subvocalization to communicate with the machine linked to the internet. It reminded me of a story that I read at least 40 years ago in which the protagonist had an implanted computer that he subvocalized to ask it questions and it responded via bone conduction that only he could hear. It also had the capability of remote sensing. I don't remember much about the story although a second such machine was implanted in another person and the two machines were able to communicate with each other directly. Anyone know of this book?
Perhaps it is Delay In Transit by F. L. Wallace.
A computer (intelligent AI) implant was talked to through sub-vocalization. It also has some abilities to scan at a distance.
Tech level was space opera with space travel and alien species common. The Galaxy had many many inhabited worlds. FTL Travel was real, though it was still time consuming. Lack of FTL Communication meant there was no easy way to communicate between systems, other than by courier. Schedules of flights between worlds were very problematic, with delays of several days common, and several weeks possible. Missing a connection could mean a delay of months or years. The protagonist's implant was top-of-the-line secret tech and he had it because of his job.
The protagonist (Cassal) had his ID stolen, preventing him from leaving through the spaceport. A stolen or counterfeit ID could be used, but the user had to get a minor lobotomy for it to work, as the ID was matched against a brain scan. This surgery was minor enough that it was a viable option taken by many, but the protagonist did not take that route. He had already been traveling for several months, and without FTL communication, contacting Earth for a replacement ID was not an option.
He finds that his implant allows him to create a duplicate ID, as it has access to his brain to do so, though it does require prodding, poking, cutting, and stabbing to get the correct brain readings.
The femme fatale of the story (Murra Foray) is an alien woman (human appearance) who has also lost her ID and is trapped on the planet. Her nickname for him is "Teddy bear".
Murra's species (Huntner), has exceptional hearing and she was able to hear everything that the Cassal and his implant had talked about, discovering how he created a duplicate ID. She render's him unconscious and steals his implant.
Cassal knows the general plans for the implant and has portions of one secretly created by various different shops, so that no one has the full plans. One such shop is an utter failure, as the amphibian aliens' stumpy fingers cause them to create a device the size of an interplanetary drive instead of something that could be implanted.
Once he successfully assembles and implants his new device, he is able to contact his previous implant, who is now willingly helping the woman. His new implant, aided by an external power supply he added, is much more powerful than the old, as it is able to communicate instantaneously over FTL distances (she is already travelling) and it is able to render her unconscious over the link.
His previous implant explains that because of a quirk of her species' brain, the lobotomy is not a viable option for her and that she had to steal the implant to create a new ID, and that her use of "Teddy Bear" indicated that she very much liked him.
The story ends with the protagonist planning on following her after he finished his mission.
1951 novel The Puppet Masters:
"The sort of phone my Section uses is not standard; the audio relay is buried surgically under the skin back of my left ear - bone conduction."
In the summer of 2007 Earth is under clandestine attack. Slug-like creatures, arriving in flying saucers, are attaching themselves to people's backs, taking control of their victims' nervous systems, and manipulating those people as puppets. The Old Man, the head of clandestine national security agency called the Section, goes to Des Moines, Iowa, with Sam and Mary, two of his best agents, to investigate a flying saucer report, but much more seriously the ominous disappearance of the six agents sent previously. They discover that the slugs are steadily taking over Des Moines, but they cannot convince the President to declare an emergency.
Sam takes two other agents and returns to Des Moines to get more evidence of the invasion.