What is BS EN IEC 60268‑16 about?
BS EN IEC 60268 discusses sound system equipment. BS EN IEC 60268‑16 is the sixteenth part of the multi-series on sound system equipment that discusses the objective rating of speech intelligibility by speech transmission index (STI). BS EN IEC 60268‑16 defines the STI model, test signals, measurement, and prediction methods.
BS EN IEC 60268‑16 provides a comprehensive manual for all types of users of the STI model in the fields of audio, communications, and acoustics. Every measurement method has limitations, and you are referred to clauses relating to limitations such as speech privacy, echo and systems using digital voice compression (vocoders). BS EN IEC 60268‑16 does not provide STI criteria for certification of transmission channels (for example- criteria for a voice-alarm system), but some typical application values are provided.
Note: BS EN IEC 60268‑16 does not cover the case of fluctuating noise on the STI, although some general comments on dealing with this complex issue are provided in 7.13 and 8.9.3.
Who is BS EN IEC 60268‑16 for?
BS EN IEC 60268‑16 on sound system equipment is useful for:
- Audio system manufacturers
- Communication devices manufacturers
- Acoustic foam and pad manufacturers
- Audio technicians
- Audio equipment companies
Why should you use BS EN IEC 60268‑16?
Speech is considered to be the major method of communication among humans. Speech Transmission Index (STI) is a measure of speech transmission quality. The STI model is an objective and validated framework for evaluating speech transmission quality for communication channels that may be affected by a wide range of acoustic and electroacoustical distortions that affect speech intelligibility BS EN IEC 60268‑16 provides a comprehensive manual for all types of users of the STI model in the fields of audio, communications, and acoustics.
The STI method provided in BS EN IEC 60268‑16 applies a specific test signal to the transmission channel and by analysing the received test signal; the speech transmission quality of the channel is derived and expressed in a value between 0 and 1, as the Speech Transmission Index (STI). Using the obtained STI value, the potential speech intelligibility can be determined.
What’s changed since the last update?
BS EN IEC 60268‑16:2020 supersedes EN 60268-16:2011.
The main changes compared to the previous version is as follows:
- The spectrum of the male speech test signal has been changed, with significant reductions in the 125 Hz and 250 Hz bands being implemented
- Some corrections to formulae have been made
- Additional information has been included on prediction and measurement procedures
- Spectrum and weighting factors for female speech have been removed
- Verification information for STI measurement devices added