diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index d11083908c..79372109fb 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -794,7 +794,7 @@ void MyAvatar::updateCollisionWithEnvironment(float deltaTime) {
 
 void MyAvatar::updateCollisionWithVoxels(float deltaTime) {
     float radius = _collisionRadius;
-    const float VOXEL_ELASTICITY = 1.4f;
+    const float VOXEL_ELASTICITY = 0.4f;
     const float VOXEL_DAMPING = 0.0;
     const float VOXEL_COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
diff --git a/libraries/particles/src/ParticleCollisionSystem.cpp b/libraries/particles/src/ParticleCollisionSystem.cpp
index 173bd0738b..c2d4093f9b 100644
--- a/libraries/particles/src/ParticleCollisionSystem.cpp
+++ b/libraries/particles/src/ParticleCollisionSystem.cpp
@@ -69,9 +69,9 @@ void ParticleCollisionSystem::checkParticle(Particle* particle) {
 void ParticleCollisionSystem::updateCollisionWithVoxels(Particle* particle) {
     glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
     float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
-    const float VOXEL_ELASTICITY = 0.4f;    // fraction of momentum conserved at collision
-    const float VOXEL_DAMPING = 0.0f;
-    const float VOXEL_COLLISION_FREQUENCY = 0.5f;
+    const float ELASTICITY = 0.4f;
+    const float DAMPING = 0.0f;
+    const float COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     VoxelDetail* voxelDetails = NULL;
     if (_voxels->findSpherePenetration(center, radius, penetration, (void**)&voxelDetails)) {
@@ -80,8 +80,8 @@ void ParticleCollisionSystem::updateCollisionWithVoxels(Particle* particle) {
         particle->collisionWithVoxel(voxelDetails);
 
         penetration /= (float)TREE_SCALE;
-        updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
-        applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING);
+        updateCollisionSound(particle, penetration, COLLISION_FREQUENCY);
+        applyHardCollision(particle, penetration, ELASTICITY, DAMPING);
         
         delete voxelDetails; // cleanup returned details
     }
@@ -90,9 +90,9 @@ void ParticleCollisionSystem::updateCollisionWithVoxels(Particle* particle) {
 void ParticleCollisionSystem::updateCollisionWithParticles(Particle* particle) {
     glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
     float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
-    const float VOXEL_ELASTICITY = 1.4f;
-    const float VOXEL_DAMPING = 0.0f;
-    const float VOXEL_COLLISION_FREQUENCY = 0.5f;
+    const float ELASTICITY = 1.4f;
+    const float DAMPING = 0.0f;
+    const float COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     Particle* penetratedParticle;
     if (_particles->findSpherePenetration(center, radius, penetration, (void**)&penetratedParticle)) {
@@ -102,7 +102,8 @@ void ParticleCollisionSystem::updateCollisionWithParticles(Particle* particle) {
         penetratedParticle->collisionWithParticle(particle);
 
         penetration /= (float)TREE_SCALE;
-        updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
+        updateCollisionSound(particle, penetration, COLLISION_FREQUENCY);
+        
         // apply a hard collision to both particles of half the penetration each
         
         float particleShare, penetratedParticleShare;
@@ -119,8 +120,8 @@ void ParticleCollisionSystem::updateCollisionWithParticles(Particle* particle) {
             particleShare = 0.5f;
             penetratedParticleShare = -0.5f;
         }
-        applyHardCollision(particle, penetration * particleShare, VOXEL_ELASTICITY, VOXEL_DAMPING);
-        applyHardCollision(penetratedParticle, penetration * penetratedParticleShare, VOXEL_ELASTICITY, VOXEL_DAMPING);
+        applyHardCollision(particle, penetration * particleShare, ELASTICITY, DAMPING);
+        applyHardCollision(penetratedParticle, penetration * penetratedParticleShare, ELASTICITY, DAMPING);
     }
 }
 
@@ -134,9 +135,9 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
     //printf("updateCollisionWithAvatars()...\n");
     glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
     float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
-    const float VOXEL_ELASTICITY = 1.4f;
-    const float VOXEL_DAMPING = 0.0f;
-    const float VOXEL_COLLISION_FREQUENCY = 0.5f;
+    const float ELASTICITY = 0.4f;
+    const float DAMPING = 0.0f;
+    const float COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     const PalmData* collidingPalm = NULL;
     
@@ -156,7 +157,7 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
             // TODO: dot collidingPalm and hand velocities and skip collision when they are moving apart.
             // apply a hard collision when ball collides with hand
             penetration /= (float)TREE_SCALE;
-            updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
+            updateCollisionSound(particle, penetration, COLLISION_FREQUENCY);
     
             // determine if the palm that collided was moving, if so, then we add that palm velocity as well...
             glm::vec3 addedVelocity = NO_ADDED_VELOCITY;
@@ -172,7 +173,7 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
             penetration /= (float)TREE_SCALE;
             updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
             glm::vec3 addedVelocity = avatar->getVelocity();
-            applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
+            applyHardCollision(particle, penetration, ELASTICITY, DAMPING, addedVelocity);
         }
     }
 
@@ -191,7 +192,7 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
             if (handData->findSpherePenetration(center, radius, penetration, collidingPalm)) {
                 // apply a hard collision when ball collides with hand
                 penetration /= (float)TREE_SCALE;
-                updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
+                updateCollisionSound(particle, penetration, COLLISION_FREQUENCY);
 
                 // determine if the palm that collided was moving, if so, then we add that palm velocity as well...
                 glm::vec3 addedVelocity = NO_ADDED_VELOCITY;
@@ -201,7 +202,7 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
                     addedVelocity = palmVelocity;
                 }
 
-                applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
+                applyHardCollision(particle, penetration, ELASTICITY, DAMPING, addedVelocity);
 
             } else if (avatar->findSpherePenetration(center, radius, penetration)) {
                 penetration /= (float)TREE_SCALE;