Here is a list of soundscapes for use in Counter-Strike: Source. An easy way of testing them is to use the playsoundscape console command, which includes limited searching for soundscape names so you shouldn't have to print out a copy of this list for reference.
Aztec
| Name | Description and Notes | 
| aztec.outdoors_e3 | An outdoor area. Continual noise of heavy rain and Crickets, Loud thunderclaps, calling birds and other jungle animal noises. | 
| aztec.outdoors | Very similar to aztec.outdoors_e3but slightly quieter and with the faint drone of an engine or generator. | 
| aztec.indoors | An Indoor area. Continual noise of Rain and Crickets, low howl of wind, occasional rumbles of thunder, falling drops and a steady electrical hum. | 
| aztec.indoors_river | The similar to aztec.indoorsbut with churning water and without the electrical hum. | 
| aztec.outdoors_river | Similar to aztec.outdoorswith additional churning water, creaking timbers and a steady electrical hum. | 
Cobble
| Name | Description and Notes | 
| cbble.indoors | A low rumble of wind / white noise with the occasional sound of shifting earth / shale. | 
| cbble.under | A slightly louder rumble of wind / white noise with occasional sounds of shifting earth / shale, birdsong, knocks, creaks and distant planes overhead. | 
| cbble.outdoors1 | A loud rumble of wind / white noise with occasional sounds of shifting earth / shale, birdsong, knocks, creaks, distant planes overhead and a moo'ing cow. | 
| cbble.outdoors2 | Very similar to cbble.outdoors1with a loud rumble of wind / white noise with occasional sounds of shifting earth / shale, birdsong, knocks, creaks and distant planes overhead. | 
Chateau
| Name | Description and Notes | 
| chateau.indoor |  | 
| chateau.outdoor |  | 
| chateau.water |  | 
| chateau.water_enc |  | 
Compound
| Name | Description and Notes | 
| compound.outdoora |  | 
| compound.indoora |  | 
| compound.outdoora |  | 
Dust
| Name | Description and Notes | 
| dust.Indoors |  | 
| dust.Outdoors1 |  | 
| dust.Outdoors2 |  | 
Dust 2
| Name | Description and Notes | 
| dust2.indoors |  | 
| dust2.outdoors |  | 
Havana
| Name | Description and Notes | 
| havana.indoors |  | 
| havana.outdoors |  | 
Inferno
| Name | Description and Notes | 
| inferno.Outside |  | 
| inferno.Inside |  | 
| inferno.LightbulbHum |  | 
| inferno.RefrigeratorHum |  | 
| inferno.CeilingFan |  | 
| inferno.AngryDog |  | 
| inferno.Cricket |  | 
| inferno.Pigeons |  | 
| inferno.TSpawn |  | 
| inferno.Birds |  | 
| inferno.FarBackCorner |  | 
| inferno.BackAlley |  | 
| inferno.TSpawnHall |  | 
| inferno.BellTowerArea |  | 
| inferno.LowerApartment |  | 
| inferno.UpperApartment |  | 
| inferno.BridgeApartment |  | 
| inferno.BackHall |  | 
| inferno.BalconyAlley |  | 
| inferno.ApartmentHalls |  | 
| inferno.SniperBalcony |  | 
| inferno.BackBalcony |  | 
| inferno.MiddleAlley |  | 
| inferno.CrawlAlley |  | 
| inferno.CrawlTunnel |  | 
| inferno.BombsiteB |  | 
| inferno.CTApartment |  | 
| inferno.BombsiteBTunnel |  | 
| inferno.DogBarkingInside |  | 
| inferno.CTTunnel |  | 
| inferno.CTSpawn |  | 
| inferno.TheRuins |  | 
| inferno.BombsiteA |  | 
| inferno.ColumnAlley |  | 
Italy
| Name | Description and Notes | 
| italy.indoor |  | 
| italy.indoor_b |  | 
| italy.indoor_t |  | 
| italy.outdoors |  | 
Office
| Name | Description and Notes | 
| office.outdoorsa |  | 
| office.garagea |  | 
| office.indoorsa |  | 
Piranesi
| Name | Description and Notes | 
| piranesi.indoor |  | 
| piranesi.outdoor |  | 
Port
| Name | Description and Notes | 
| port.Outside |  | 
| port.LightHum |  | 
| port.LightHum2 |  | 
| port.MetalStress |  | 
| port.TSpawn |  | 
| port.TankFarmRoad |  | 
| port.TankFarm |  | 
| port.Pier |  | 
| port.AroundTheWarehouse |  | 
| port.Warehouse |  | 
| port.TunnelTone |  | 
| port.WarehouseTunnel |  | 
| port.TunnelA3 |  | 
| port.TunnelA2 |  | 
| port.TunnelA1 |  | 
| port.Docks |  | 
| port.Ship |  | 
Prodigy
| Name | Description and Notes | 
| prodigy.computers |  | 
| prodigy.vents |  | 
| prodigy.tunnels |  | 
| prodigy.hangar |  | 
Tides
| Name | Description and Notes | 
| tides.tunnel |  | 
| tides.courtyard |  | 
Train
| Name | Description and Notes | 
| train.Outside |  | 
| train.Dumpster |  | 
| train.Traffic |  | 
| train.Tank1 |  | 
| train.Tank2 |  | 
| train.BombTarget |  | 
| train.Birds |  | 
| train.TSpawn |  | 
| train.TWalkway |  | 
| train.BackAlley |  | 
| train.BackCorner |  | 
| train.SideAlley |  | 
| train.CourtyardA |  | 
| train.BombsiteA |  | 
| train.CTSpawn |  | 
| train.BombsiteBCatwalk |  | 
| train.catwalk |  | 
| train.BombsiteB |  | 
| train.BackHall |  | 
| train.BrickRoom |  | 
| train.Restroom |  | 
| train.LockerRoom |  | 
| train.BreakRoom |  | 
| train.SniperNest |  | 
| train.Middle |  |