chennai an audio technology will be installed in all metro stations to enable passengers wearing hearing aids and cochlear implants to hear all audio passenger and train announcements clearly chennai metro rail limited cmrl has floated a tender to install test and commission audiofrequency induction loop afils an assistive listening technology that will be connected to the public information display systems pids at stations afils mostly used to eliminate background noise will create a magnetic field and transmit sound through a wireless loop to telecoil of hearing aidsreceiveraccording to the tender cmrl will install 43 afils systems at airport meenambakkam nanganallur road alandur st thomas mount guindy and little mount stations and connect them to pids displays on each platform and on the concourse level as most announcements at metro stations are prerecorded people wearing hearing aids often hear echo or the audio is feeble we are installing afils so that the background noise and the echo gets cut and the sound is clear a cmrl official said it was previously installed at a few stations but it stopped functioning at a few stationsofficials said the system has a single or an array of loop cables an induction loop amplifier along with pids with the latter connected to the induction loop amplifier the loop of cable creates a magnetic field signal in the area of coverage and transmits the audio signal as a wireless signal which is picked up by the telecoil of the hearing aids cochlear implants and other loop receiver devices to use afils the user must be within the coverage area the stations will have signage to indicate coverage area the user must switch the hearing aid to the t position to hear announcements vaishnavi jayakumar of disability rights alliance said accessibility of real time transit communication tends to exclude citizens with sensory disabilities the audio induction loop will transform the communication experience for people with telecoilcompatible hearing aids since this is to our knowledge the first in a public space in india we are hopeful the rest of india will wake up and this becomes the norm this is an adjunct facility to be provided at counter platform and coaches she said