From Halopedia, the Halo wiki
The Interrogator is a device developed by the Office of Naval Intelligence. It is a small portable computer used to translate Covenant languages and intended for interrogation, hence the name. It features a microphone, speakers, a digital ink keyboard and every piece of linguistic data the UNSC has on the Covenant languages. However, as the available data is scarce, the device's translation capabilities are very limited. For example, it failed to translate the speech of the Yanme'e nicknamed Hopalong, until the creature tampered with the device's inner circuitry, making direct translation possible. Normally, the Interrogator speaks in the accent of the Midwestern United States.
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