Speech Intelligibility Bandwidth

by Pat Brown

How much audio bandwidth is required for good speech intelligibility? You may be surprised. This video will help form your “SI bandwidth philosophy.”

It’s important to have a defensible philosophy with regard to the required bandwidth for good speech intelligibility.

The audio bandwidth of any modern electronic component can easily extend to 20 kHz, so why is this even an issue? One reason is that audio streaming and video conferencing systems must minimize their data rate for real-time use. A lower data rate means less audio bandwidth. For this reason the headset microphones used in these systems are often low pass filtered at around 8 kHz.

Another is that paging and background music systems have a practical high frequency limit, determined by the loudspeaker’s frequency response, the loudspeaker-to-listener distance, and the listener’s angle to the loudspeaker. A system that can “produce 20 kHz everywhere” will require far more loudspeakers than one that only goes to 10 kHz.

Is that high enough? You be the judge.   pb