diff --git a/include/mondata.h b/include/mondata.h
index 5c86faa45..7757dd275 100644
--- a/include/mondata.h
+++ b/include/mondata.h
@@ -29,7 +29,7 @@
 #define resists_poison(mon) ((mon_resistancebits(mon) & MR_POISON) != 0)
 #define resists_acid(mon) ((mon_resistancebits(mon) & MR_ACID) != 0)
 #define resists_sonic(mon) ((mon_resistancebits(mon) & MR_SONIC) != 0 \
-                            || mon_underwater(mon))
+                            || !has_head((mon)->data) || mon_underwater(mon))
 #define resists_ston(mon) ((mon_resistancebits(mon) & MR_STONE) != 0)
 #define resists_psychic(mon) ((mon_resistancebits(mon) & MR_PSYCHIC) != 0)
 #define resists_clob(mon) ((mon_resistancebits(mon) & MR_CLOB) != 0)
diff --git a/src/monst.c b/src/monst.c
index 4b56d6923..0283e0ad4 100644
--- a/src/monst.c
+++ b/src/monst.c
@@ -1832,7 +1832,7 @@ NEARDATA struct permonst mons[] = {
         LVL(3, 1, 3, 0, 0), (G_GENO | 4),
         A(ATTK(AT_BITE, AD_PHYS, 2, 6), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(200, 200, MS_SILENT, MZ_SMALL), MR_SONIC, 0,
+        SIZ(200, 200, MS_SILENT, MZ_SMALL), 0, 0,
         M1_CLING | M1_HIDE | M1_ANIMAL | M1_NOEYES | M1_NOLIMBS | M1_CARNIVORE
             | M1_NOTAKE,
         M2_HOSTILE, 0, 0, 0, 4, CLR_GRAY),
@@ -1840,7 +1840,7 @@ NEARDATA struct permonst mons[] = {
         LVL(5, 1, 0, 0, 0), (G_GENO | 2),
         A(ATTK(AT_BITE, AD_PHYS, 3, 6), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), MR_SONIC, 0,
+        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), 0, 0,
         M1_CLING | M1_HIDE | M1_ANIMAL | M1_NOEYES | M1_NOLIMBS | M1_CARNIVORE
             | M1_NOTAKE,
         M2_HOSTILE, 0, M4_VULNERABLE_ACID, 0, 6, CLR_CYAN),
@@ -1848,7 +1848,7 @@ NEARDATA struct permonst mons[] = {
         LVL(7, 1, 0, 0, 0), (G_GENO | 1),
         A(ATTK(AT_BITE, AD_PHYS, 4, 6), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), MR_ACID | MR_SONIC, 0,
+        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), MR_ACID | 0, 0,
         M1_CLING | M1_HIDE | M1_ANIMAL | M1_NOEYES | M1_NOLIMBS | M1_CARNIVORE
             | M1_NOTAKE,
         M2_HOSTILE, 0, 0, 0, 9, CLR_WHITE),
@@ -1856,7 +1856,7 @@ NEARDATA struct permonst mons[] = {
         LVL(8, 1, 0, 0, 0), (G_GENO),
         A(ATTK(AT_BITE, AD_PHYS, 8, 6), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), MR_ACID | MR_FIRE | MR_SONIC, 0,
+        SIZ(400, 300, MS_SILENT, MZ_MEDIUM), MR_ACID | MR_FIRE | 0, 0,
         M1_CLING | M1_HIDE | M1_ANIMAL | M1_NOEYES | M1_NOLIMBS | M1_CARNIVORE
             | M1_NOTAKE,
         M2_HOSTILE, 0, 0, 0, 12, CLR_BLUE),
@@ -1865,7 +1865,7 @@ NEARDATA struct permonst mons[] = {
         A(ATTK(AT_BITE, AD_PHYS, 16, 6), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(400, 300, MS_SILENT, MZ_MEDIUM), 
-        MR_ACID | MR_ELEC | MR_FIRE | MR_COLD | MR_SONIC, 0,
+        MR_ACID | MR_ELEC | MR_FIRE | MR_COLD | 0, 0,
         M1_CLING | M1_HIDE | M1_ANIMAL | M1_NOEYES | M1_NOLIMBS | M1_CARNIVORE
             | M1_NOTAKE,
         M2_HOSTILE, 0, 0, 0, 20, CLR_BRIGHT_MAGENTA),
@@ -2763,7 +2763,7 @@ NEARDATA struct permonst mons[] = {
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_SMALL),
         MR_FIRE | MR_COLD | MR_ELEC | MR_DISINT | MR_SLEEP | MR_POISON
-            | MR_ACID | MR_STONE | MR_SONIC,
+            | MR_ACID | MR_STONE,
         0, M1_FLY | M1_BREATHLESS | M1_AMORPHOUS | M1_NOEYES | M1_NOLIMBS
                | M1_NOHEAD | M1_MINDLESS | M1_UNSOLID | M1_NOTAKE,
         M2_HOSTILE | M2_NEUTER, M3_INFRAVISIBLE, 0, 0, 5, CLR_YELLOW),
@@ -2773,7 +2773,7 @@ NEARDATA struct permonst mons[] = {
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_SMALL),
         MR_FIRE | MR_COLD | MR_ELEC | MR_DISINT | MR_SLEEP | MR_POISON
-            | MR_ACID | MR_STONE | MR_SONIC,
+            | MR_ACID | MR_STONE,
         0,
         M1_FLY | M1_BREATHLESS | M1_AMORPHOUS | M1_NOEYES | M1_NOLIMBS
             | M1_NOHEAD | M1_MINDLESS | M1_UNSOLID | M1_SEE_INVIS | M1_NOTAKE,
@@ -2784,7 +2784,7 @@ NEARDATA struct permonst mons[] = {
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_SMALL),
         MR_FIRE | MR_COLD | MR_ELEC | MR_DISINT | MR_SLEEP | MR_POISON
-        | MR_ACID | MR_STONE | MR_SONIC,
+        | MR_ACID | MR_STONE,
         0, M1_FLY | M1_BREATHLESS | M1_AMORPHOUS | M1_NOEYES | M1_NOLIMBS
            | M1_NOHEAD | M1_MINDLESS | M1_UNSOLID | M1_NOTAKE,
         M2_HOSTILE | M2_NEUTER, M3_INFRAVISIBLE, 0, 0, 9, CLR_BRIGHT_MAGENTA),
@@ -2795,7 +2795,7 @@ NEARDATA struct permonst mons[] = {
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_SMALL),
         MR_FIRE | MR_COLD | MR_ELEC | MR_DISINT | MR_SLEEP | MR_POISON
-            | MR_ACID | MR_STONE | MR_SONIC, 0, 
+            | MR_ACID | MR_STONE, 0, 
         M1_FLY | M1_BREATHLESS | M1_AMORPHOUS | M1_NOEYES | M1_NOLIMBS
             | M1_NOHEAD | M1_MINDLESS | M1_UNSOLID | M1_NOTAKE,
         M2_HOSTILE | M2_NEUTER | M2_WANDER, 
@@ -3147,7 +3147,7 @@ NEARDATA struct permonst mons[] = {
         A(ATTK(AT_BITE, AD_PHYS, 2, 8), 
           ATTK(AT_SCRE, AD_PIER, 2, 8),
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(30, 30, MS_SHRIEK, MZ_MEDIUM), MR_SONIC, 0,
+        SIZ(30, 30, MS_SHRIEK, MZ_MEDIUM), 0, 0,
         M1_FLY | M1_ANIMAL | M1_NOHANDS | M1_CARNIVORE,
         M2_WANDER | M2_HOSTILE | M2_GREEDY | M2_JEWELS, 
         M3_INFRAVISIBLE, 0, 0, 11, CLR_BLACK),
@@ -3158,7 +3158,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_BITE, AD_PHYS, 1, 6),
           ATTK(AT_SCRE, AD_SONG, 1, 6),
           NO_ATTK, NO_ATTK),
-        SIZ(130, 130, MS_SEDUCE, MZ_MEDIUM), MR_SONIC, 0,
+        SIZ(130, 130, MS_SEDUCE, MZ_MEDIUM), 0, 0,
         M1_FLY | M1_ANIMAL | M1_CARNIVORE,
         M2_WANDER | M2_HOSTILE, 
         M3_INFRAVISIBLE | M3_TRAITOR, 0, 0, 10, CLR_GRAY),
@@ -3328,7 +3328,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 2, 4),
           NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(WT_BABY_DRGN, NUT_BABY_DRGN, MS_ROAR, MZ_HUGE),
-        MR_POISON | MR_SONIC | MR_DRAIN, 0,
+        MR_POISON | MR_DRAIN, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_GREEDY | M2_JEWELS,
         M3_TRAITOR, 0, MH_DRAGON, 13, CLR_MAGENTA),
@@ -3429,7 +3429,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 2, 4),
           ATTK(AT_CLAW, AD_PHYS, 2, 4),
           NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(WT_BABY_DRGN, NUT_BABY_DRGN, MS_ROAR, MZ_HUGE), MR_ACID | MR_STONE | MR_SONIC, 0,
+        SIZ(WT_BABY_DRGN, NUT_BABY_DRGN, MS_ROAR, MZ_HUGE), MR_ACID | MR_STONE, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_CARNIVORE | M1_ACID,
         M2_HOSTILE | M2_STRONG | M2_GREEDY | M2_JEWELS, M3_TRAITOR, 0,
         MH_DRAGON, 13, CLR_YELLOW),
@@ -3444,7 +3444,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           ATTK(AT_NONE, AD_CNCL, 0, 0)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_SONIC, 0,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 0, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3457,7 +3457,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           NO_ATTK),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_COLD | MR_SONIC, 0,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_COLD, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3470,7 +3470,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           ATTK(AT_NONE, AD_STUN, 2, 6)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_SONIC, 0,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 0, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
           | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3484,7 +3484,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           ATTK(AT_NONE, AD_DRLI, 0, 1)),
         SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 
-        MR_POISON | MR_SONIC | MR_DRAIN, 0,
+        MR_POISON | MR_DRAIN, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE | M1_POIS,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3498,7 +3498,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           ATTK(AT_NONE, AD_FIRE, 0, 1)),
         SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 
-        MR_FIRE | MR_SONIC, MR_FIRE,
+        MR_FIRE, MR_FIRE,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS
             | M1_OVIPAROUS | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3511,7 +3511,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           ATTK(AT_NONE, AD_COLD, 0, 6)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_COLD | MR_SONIC, MR_COLD,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_COLD, MR_COLD,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3524,7 +3524,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           ATTK(AT_NONE, AD_SLOW, 0, 2)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_SLEEP | MR_SONIC, MR_SLEEP,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_SLEEP, MR_SLEEP,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
         M3_TRAITOR, 0, MH_DRAGON, 30, CLR_ORANGE),
@@ -3548,7 +3548,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           ATTK(AT_NONE, AD_DISN, 0, 0)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_DISINT | MR_SONIC, MR_DISINT,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_DISINT, MR_DISINT,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3561,7 +3561,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           ATTK(AT_NONE, AD_ELEC, 0, 2)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_ELEC | MR_SONIC, MR_ELEC,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_ELEC, MR_ELEC,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
         M3_TRAITOR, 0, MH_DRAGON, 30, CLR_BLUE),
@@ -3573,7 +3573,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           ATTK(AT_NONE, AD_DRST, 0, 1)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_POISON | MR_SONIC, MR_POISON,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_POISON, MR_POISON,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE | M1_POIS,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3587,7 +3587,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_ENGL, AD_DGST, 2, 10),
           NO_ATTK),
         SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 
-        MR_FIRE | MR_SONIC | MR_SICK, 0,
+        MR_FIRE | MR_SICK, 0,
         M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS | M1_OVIPAROUS
             | M1_CARNIVORE,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3600,7 +3600,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_WRAP, 2, 10), 
           ATTK(AT_NONE, AD_RUST, 0, 2)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_SONIC, 0,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), 0, 0,
         M1_SWIM | M1_AMPHIBIOUS | M1_NOHANDS | M1_SEE_INVIS
             | M1_OVIPAROUS | M1_CARNIVORE | M1_UNSOLID,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3613,7 +3613,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_PHYS, 4, 4),
           ATTK(AT_ENGL, AD_DGST, 2, 10), 
           ATTK(AT_NONE, AD_ACID, 0, 4)),
-        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_ACID | MR_STONE | MR_SONIC,
+        SIZ(WT_DRAGON, NUT_DRAGON, MS_ROAR, MZ_GIGANTIC), MR_ACID | MR_STONE,
         MR_STONE, M1_FLY | M1_THICK_HIDE | M1_NOHANDS | M1_SEE_INVIS
             | M1_OVIPAROUS | M1_CARNIVORE | M1_ACID,
         M2_HOSTILE | M2_STRONG | M2_NASTY | M2_GREEDY | M2_JEWELS | M2_MAGIC,
@@ -3655,7 +3655,7 @@ NEARDATA struct permonst mons[] = {
         A(ATTK(AT_ENGL, AD_PHYS, 1, 10), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_HUGE),
-        MR_POISON | MR_STONE | MR_SONIC | MR_SICK, 0,
+        MR_POISON | MR_STONE | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_UNSOLID | M1_FLY,
         M2_STRONG | M2_NEUTER, 0, 0, 0, 10, CLR_CYAN),
@@ -3669,7 +3669,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_NONE, AD_FIRE, 0, 4), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_HUGE), 
-        MR_FIRE | MR_POISON | MR_STONE | MR_SONIC | MR_SICK, 0,
+        MR_FIRE | MR_POISON | MR_STONE | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_UNSOLID | M1_FLY | M1_NOTAKE,
         M2_STRONG | M2_NEUTER, M3_INFRAVISIBLE, M4_VULNERABLE_COLD, 0, 10, CLR_YELLOW),
@@ -3690,7 +3690,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_CLAW, AD_BLND, 1, 6),
           NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(2500, 0, MS_SILENT, MZ_LARGE),
-        MR_FIRE | MR_COLD | MR_POISON | MR_STONE | MR_SONIC | MR_SICK, 0,
+        MR_FIRE | MR_COLD | MR_POISON | MR_STONE | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_WALLWALK | M1_UNSOLID | M1_THICK_HIDE | M1_AMPHIBIOUS | M1_SWIM,
         M2_STRONG | M2_NEUTER, 0, 0, 0, 11, CLR_BROWN),
@@ -3701,7 +3701,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_ENGL, AD_ACID, 4, 4),
           NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(2500, 0, MS_SILENT, MZ_HUGE),
-        MR_FIRE | MR_COLD | MR_POISON | MR_ACID | MR_SONIC | MR_SICK, 0,
+        MR_FIRE | MR_COLD | MR_POISON | MR_ACID | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_WALLWALK | M1_THICK_HIDE | M1_UNSOLID | M1_AMPHIBIOUS | M1_SWIM,
         M2_STRONG | M2_NEUTER, 0, 0, 0, 12, CLR_BRIGHT_GREEN),
@@ -3723,7 +3723,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_ENGL, AD_FIRE, 4, 4),
           NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(0, 0, MS_SILENT, MZ_LARGE), 
-        MR_FIRE | MR_ACID | MR_SONIC | MR_SICK, 0,
+        MR_FIRE | MR_ACID | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_THICK_HIDE | M1_NOTAKE,
         M2_STRONG | M2_NEUTER, M3_INFRAVISIBLE, 0, 0, 12, CLR_ORANGE),
@@ -3734,7 +3734,7 @@ NEARDATA struct permonst mons[] = {
           ATTK(AT_NONE, AD_RUST, 0, 0), 
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(2500, 0, MS_SILENT, MZ_HUGE), 
-        MR_POISON | MR_STONE | MR_SONIC | MR_SICK, 0,
+        MR_POISON | MR_STONE | MR_SICK, 0,
         M1_NOEYES | M1_NOLIMBS | M1_NOHEAD | M1_MINDLESS | M1_BREATHLESS
             | M1_UNSOLID | M1_AMPHIBIOUS | M1_SWIM,
         M2_STRONG | M2_NEUTER, 0, M4_VULNERABLE_ELEC, 0, 10, CLR_BLUE),
@@ -5438,7 +5438,7 @@ struct permonst _mons2[] = {
           ATTK(AT_CLAW, AD_CLOB, 2, 18),
           NO_ATTK, NO_ATTK),
         SIZ(1200, 0, MS_SILENT, MZ_HUMAN),
-        MR_COLD | MR_SLEEP | MR_POISON | MR_SONIC | MR_DRAIN | MR_SICK, 0, 
+        MR_COLD | MR_SLEEP | MR_POISON | MR_DRAIN | MR_SICK, 0, 
         M1_BREATHLESS | M1_HUMANOID, 
         M2_STALK | M2_HOSTILE | M2_COLLECT | M2_STRONG, 
         M3_INFRAVISION | M3_ACCURATE | M3_BERSERK, 
@@ -5451,7 +5451,7 @@ struct permonst _mons2[] = {
           ATTK(AT_SCRE, AD_LOUD, 4, 4),
           NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(WT_HUMAN, 0, MS_SPELL, MZ_HUMAN), 
-        MR_COLD | MR_SLEEP | MR_POISON | MR_SONIC | MR_DRAIN | MR_SICK,
+        MR_COLD | MR_SLEEP | MR_POISON | MR_DRAIN | MR_SICK,
         0, M1_BREATHLESS | M1_HUMANOID | M1_SEE_INVIS,
         M2_NOPOLY | M2_STALK | M2_STRONG | M2_HOSTILE | M2_MALE
             | M2_COLLECT,
@@ -6166,7 +6166,7 @@ struct permonst _mons2[] = {
           ATTK(AT_SCRE, AD_GIBB, 1, 8),
           ATTK(AT_STNG, AD_LARV, 2, 3),
           NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(WT_HUMAN, 400, MS_WAIL, MZ_HUMAN), MR_SONIC, 0, 
+        SIZ(WT_HUMAN, 400, MS_WAIL, MZ_HUMAN), 0, 0, 
         M1_HUMANOID | M1_OMNIVORE, M2_NOPOLY | M2_COLLECT, 
         M3_INFRAVISIBLE | M3_TRAITOR, 0, MH_HUMAN, 9, CLR_GRAY),
     MON("werebear", S_HUMAN,                                  /* SpliceHack */