1810, member of a gang of murderers and robbers in India who strangled their victims, from Marathi thag, thak cheat, swindler, Hindi thag, perhaps from Sanskrit sthaga-s cunning, fraudulent, possibly from sthagayati (he) covers, conceals, from PIE root *(s)teg- cover (see stegosaurus).
It may also occur in one ear or both ears. The most common reason for muffled hearing is conductive hearing loss that can be caused by a variety of factors or medical conditions including a build up of ear wax and ear infections. In most cases, however, it is treatable and does not lead to permanent hearing damage.
Always treat it seriously when you hear a carbon monoxide detector beeping. The beeping or chirping sound is usually quite noticable but nowehere near as loud as when an actual alarm is activated. Detectors may beep for different reasons but it is always a sign that the detector needs attention.