diff --git a/Project.toml b/Project.toml
index 1da9d61..74510d6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -6,6 +6,7 @@ version = "0.2.0"
 [deps]
 DSP = "717857b8-e6f2-59f4-9121-6e50c889abd2"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+LoopVectorization = "bdcacae8-1622-11e9-2a5c-532679323890"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
diff --git a/src/ISM.jl b/src/ISM.jl
index 2ec2bb5..580cb15 100644
--- a/src/ISM.jl
+++ b/src/ISM.jl
@@ -196,10 +196,11 @@ function ISM_RectangularRoom_core!(
                     i_e = min(floor(Int, (τ + Wd / 2) * fs) + 1, Nh) # end
 
                     # Insert yet another impulse into transfer function
-                    for i ∈ i_s:i_e
+                    @turbo for i ∈ i_s:i_e
                         t = (i - 1) / fs - τ # time signature
                         w = 0.5 * (1.0 + cos(2π * t / Wd)) # Hann window
-                        h[i] += w * A * sinc(fs * t) # sinc
+                        x = π * fs * t + eps()
+                        h[i] += w * A * sin(x)/x
                     end
                 end
             end