Large Area Assistive Listening Systems: Review and Recommendations

2.3.1 Standards

There are no standards that we are aware of that specifically cover the unique aspects of IR systems. The New York Standards, quoted in respect to IL and FM installations, do not provide this information; rather these standards basically focus on the electroacoustic output from the IR receivers. When the NYS standards were drafted in l988‒89, the manufacturers could not reach a consensus regarding minimum energy level of the IR light at a set distance from the emitters. Instead a general recommendation was made that the minimum light level must be sufficient so that receivers could produce the required output signal specifications (Johnstone l999).