ST-CS-10-339-75
March 2002

7.  Gunfire Audibility  (S)

Players using A3D sound are able to hear approximately twice as far as players using EAX or no 3D sound.

This is of course a huge advantage, akin to being able to see through walls, since any sound produced by a player gives his position away and crucially the listening player has not in turn given his position away since his short-hearing opponent cannot yet hear him.

A test map, te_audio, was produced. This is a very long thin map, approximately 8000 world units long. A measuing ruler runs down the length of the map. A player with a weapon stands at the top end of the ruler, and the player listening moves down the ruler until he can no longer hear the gunfire of the player at the top of the ruler.

The ruler is marked every hundred world units, with a numeral every thousand world units to aid in finding distance values.

Note that a prototype test map was originally produced, which was square rather than long and thin, in case the long and thin design artifically reinforced sonic propogation. Comparing measurements on the prototype map and te_audio show that this effect does not occur, probably because on these maps there are no walls, the sides of the map are sky.

The results are as follows; note that (S) denotes silencer on, (T) denotes triple fire mode for the Glock18 pistol. Zooming on any weapon does not affect audibility.

Cartridges refers to the sound of cartridges ejected from a weapon hitting the ground. Please refer to the next section covering silencers for more information on this subject.

Note that the AWP and HE grenades are stunningly loud. With A3D they can literally be heard right the way across the majority of maps.

In the authors opinion, it makes good sense for professional clans, competing for tens of thousands of dollars in prizes in CS tournaments, to invest in A3D hardware since the cards are about twenty dollars a piece.

Windows is entirely capable of supporting multiple sound cards concurrently; users simply switch between the sound card in use at any time. Unfortunately, Aureal Inc., the designers of the A3D chipset, went of business some years ago. As such, A3D drivers only exist for Windows 9x.

Note however that Half-life requires version 2 (two) of the A3D sound API. Only cards built with the Aureal 8830 chipset support this version; all other cards (including the A3D support on all SoundBlaster cards) only support version 1 (one) of the A3D API.

If Half-life is configured to use A3D on a card which does not support A3D or supports only version 1 of the API then the A3D setting will be ignored, and normal sound (or EAX, if that is also configured to be active) is used.

The author suspects (but has not yet tested) that the order in which a 3D sound API is chosen in the config.cfg file is important. If s_eax is listed before s_a3d, EAX is chosen, and vis versa, with the caveat that if the sound card does not support the selected API then that setting is ignored. Since config.cfg is sorted and rewritten by Half-life every time it runs, and s_a3d is alphabetically higher than s_eax, A3D appears to be chosen in preference (if available) when both A3D and EAX are set to be active in the audio configuration menu.

Also note that in-game voice comms do not currently work with A3D enabled. It is necessary to use a third-party voice-over-IP client.