TOD script editing (sounds)

hello! I think I need help with putting sounds into my Time Of day script (TOD). I am wanting to be so anywhere you can here it but not under water. I also would like if you can make it so if its morning its a day sound and if its night its a night sound.

 var slider : float;
 var slider2 : float;
 var Hour : float;
 private var Tod: float;
 
 var sun: Light;
 
 var speed = 50;
 
 var NightFogColor : Color;
 var DuskFogColor : Color;
 var MorningFogColor : Color;
 var MiddayFogColor : Color;
 
 var NightAmbientLight : Color;
 var DuskAmbientLight : Color;
 var MorningAmbientLight : Color;
 var MiddayAmbientLight : Color;
 
 var NightTint : Color;
 var DuskTint : Color;
 var MorningTint : Color;
 var MiddayTint : Color;
 
 var SkyBoxMaterial1 : Material;
 var SkyBoxMaterial2 : Material;
 
 var SunNight : Color;
 var SunDay : Color;
 
 //Uncheck IncludeWater if you are not interested in using this.
 var Water : GameObject;
 var IncludeWater = false;
 var WaterNight : Color;
 var WaterDay : Color;
 
 
 
 function OnGUI () {
 
 if(slider >= 1.0)
 {
     slider = 0;
 }
 
 slider= GUI.HorizontalSlider( Rect(20,20,200,30), slider, 0,1.0);
 Hour= slider*24;
 Tod= slider2*24;
 sun.transform.localEulerAngles = Vector3((slider*360)-90, 0, 0);
 slider = slider +Time.deltaTime/speed;
 sun.color = Color.Lerp (SunNight, SunDay, slider*2);
 //Uncheck IncludeWater if you are not interested in using this.
 if (IncludeWater == true)
 {
     Water.renderer.material.SetColor("_horizonColor", Color.Lerp (WaterNight, WaterDay, slider2*2-0.2));
 }
 
 if(slider<0.5){
 slider2= slider;
 }
 if(slider>0.5){
 slider2= (1-slider);
 }
 sun.intensity = (slider2-0.2)*1.7;
 
 
 if(Tod<4){
 //it is Night
 RenderSettings.skybox=SkyBoxMaterial1;
 RenderSettings.skybox.SetFloat("_Blend", 0);
 SkyBoxMaterial1.SetColor ("_Tint", NightTint);
 RenderSettings.ambientLight = NightAmbientLight;
 RenderSettings.fogColor = NightFogColor;
 }
 if(Tod>4&&Tod<6){
 RenderSettings.skybox=SkyBoxMaterial1;
 RenderSettings.skybox.SetFloat("_Blend", 0);
 RenderSettings.skybox.SetFloat("_Blend", (Tod/2)-2);
 SkyBoxMaterial1.SetColor ("_Tint", Color.Lerp (NightTint, DuskTint, (Tod/2)-2) );
 RenderSettings.ambientLight = Color.Lerp (NightAmbientLight, DuskAmbientLight, (Tod/2)-2);
 RenderSettings.fogColor = Color.Lerp (NightFogColor,DuskFogColor, (Tod/2)-2);
 //it is Dusk
 
 }
 if(Tod>6&&Tod<8){
 RenderSettings.skybox=SkyBoxMaterial2;
 RenderSettings.skybox.SetFloat("_Blend", 0);
 RenderSettings.skybox.SetFloat("_Blend", (Tod/2)-3);
 SkyBoxMaterial2.SetColor ("_Tint", Color.Lerp (DuskTint,MorningTint,  (Tod/2)-3) );
 RenderSettings.ambientLight = Color.Lerp (DuskAmbientLight, MorningAmbientLight, (Tod/2)-3);
 RenderSettings.fogColor = Color.Lerp (DuskFogColor,MorningFogColor, (Tod/2)-3);
 //it is Morning
 
 }
 if(Tod>8&&Tod<10){
 RenderSettings.ambientLight = MiddayAmbientLight;
 RenderSettings.skybox=SkyBoxMaterial2;
 RenderSettings.skybox.SetFloat("_Blend", 1);
 SkyBoxMaterial2.SetColor ("_Tint", Color.Lerp (MorningTint,MiddayTint,  (Tod/2)-4) );
 RenderSettings.ambientLight = Color.Lerp (MorningAmbientLight, MiddayAmbientLight, (Tod/2)-4);
 RenderSettings.fogColor = Color.Lerp (MorningFogColor,MiddayFogColor, (Tod/2)-4);
 
 //it is getting Midday
 
 }
 }