Chu & Warnock’s long term speech data, together with that for a 4128C head & torso simulator (HATS) could be useful if you do not already know about it – see
For a simple comparison, we converted these data to directivity index (DI), and compared to our measurements of a head-sized loudspeaker (NTI Talkbox). Up to 630 Hz third oct band, the DI values of humans, HATS and NTI Talkbox are similar (mainly around 2 to 3 dB), with the talkbox becoming increasingly directional at higher frequencies. Roughly speaking, there is about a 3 dB difference in directivity index between 800 Hz and 4000 Hz 1/3-oct bands, and a much larger difference above that. I expect similar results would occur for head-sized loudspeakers with similar diameter drivers (about 800 mm).
We did some other tests varying mouth aperture on a HATS, which significantly changed directivty at some frequencies, but did not change measured Speech Transmission Index values in three normal rooms. The effect of directivity (based on theoretical modeling) should be maximum at somewhat less than a critical distance, which in many situations is too close to be of consequence.
From: AUDITORY -
Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxxxxxxx] On Behalf Of Jose Almagro
I think every loudspeaker of the same size a
human head has would comply. Norsonic recommends using a
2009/3/4 Tony Miller <antonio.miller@xxxxxxxxx>
Suggesting a head and torso simulator (HATS) might be overkill on your
budget if you are just interested in getting the directivity of an average
On Wed, Mar 4, 2009 at 11:10 AM, Pang <sound08@xxxxxxx> wrote: