Amplified (high gain) telephone testing includes performance tests to measure sound amplification (volume control gain), tone control (frequency response), simulated use for hearing aid users will meeting noise and distortion requirements for the required amplified settings. Additional tests characterize the alerter (ringer) acoustic output amplification.
Measuring the handset and speakerphone acoustic output characteristics involves determining the combinations of tone control settings for meeting high frequency emphasis (HFE) in concert with three levels of amplification settings related to hearing loss.
Measuring the alerter (ringer) acoustic output characteristics involves determining the frequency spectrum in concert with three levels of amplification settings related to hearing loss:
Measuring the AEC and Attenuation characteristics is an important parameter as a poorly designed AEC can cause the far-end party to hear themselves during converstation. If send and/or receive path attenuation is used to control echo then proper switching is required to avoid conversational fustration for the near-end and far-end parties.