IEC EN 60268-16 Audio System Equipment Part 16: Test for Objective Evaluation of Speech Intelligibility by Speech Transmission Index

EUROLAB, with its state-of-the-art accredited laboratories and expert team, provides precise and fast testing services within the scope of IEC EN 60268-16 testing. IEC 60268-16 defines the STI model, test signals, measurement and estimation methods. The purpose of this standard is to provide comprehensive guidance for any user of the STI model in the fields of sound, communications and acoustics.

Each measurement method has its limitations and the reader is directed to the articles about the limitations. such as systems using speech privacy, echo and digital audio compression (vocoder). This standard does not cover the fluctuating noise situation in STI.

This edition includes the following important technical changes from the previous edition:

• The spectrum of the male speech test signal was altered by applying significant reductions in the 125 Hz and 250 Hz bands;
• Some corrections have been made to the formulas;
• Additional information on estimation and measurement procedures is included;
• Spectrum and weighting factors have been removed for female speech;
• Added verification information for STI meters.

Speech is considered the main method of communication between people. In many cases, the speech signal is distorted by the signal path or transmission channel between the speaker and the listener, resulting in reduced intelligibility of speech at the listener's location.

The STI method applies a specific test signal to the transmission channel and analyzes the received test signal; The speech transmission quality of the channel is derived and expressed as the Speech Transmission Index (STI) with a value between 0 and 1. Potential speech intelligibility can be determined using the obtained STI value.

EUROLAB assists manufacturers with IEC EN 60268-16 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.