diff --git a/applications/RoomAcoustics/ita_speech_transmission_index.m b/applications/RoomAcoustics/ita_speech_transmission_index.m
index 7266d3eb846c6ffae812e5fdcd80411e108294c2..86c7f5a1924980de790007077eb9d6b9ba5983f6 100644
--- a/applications/RoomAcoustics/ita_speech_transmission_index.m
+++ b/applications/RoomAcoustics/ita_speech_transmission_index.m
@@ -129,7 +129,7 @@ if sArgs.analytic
     % RT for analytic result
     RT      = ita_roomacoustics(ir,'T30','freqRange',[125 8000],'bandsperoctave',1);
     RT      = RT.T30.freq;
-    m_analytic = 1./sqrt(1 + (2*pi.*bsxfun(@times,fm,RT)./13.8).^2);
+    m_analytic = 1./(bsxfun(@times,sqrt(1 + (2*pi.*bsxfun(@times,fm,RT)./13.8).^2),(1+10.^(-SNR.'./10))));
     m_analytic = min(bsxfun(@times,m_analytic,correctionTerm),1);
     SNR_eff_analytic = min(max(real(10.*log10(m_analytic./(1-m_analytic))),-15),15);
     TI_analytic = (SNR_eff_analytic + 15)./30;