diff --git a/app/src/main/kotlin/com/tutpro/baresip/AudioActivity.kt b/app/src/main/kotlin/com/tutpro/baresip/AudioActivity.kt
index 40bcc035..a1dcc4f6 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/AudioActivity.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/AudioActivity.kt
@@ -15,6 +15,7 @@ import com.tutpro.baresip.databinding.ActivityAudioBinding
 class AudioActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityAudioBinding
+    private lateinit var micGain: EditText
     private lateinit var opusBitRate: EditText
     private lateinit var opusPacketLoss: EditText
     private lateinit var aec: CheckBox
@@ -24,6 +25,7 @@ class AudioActivity : AppCompatActivity() {
     private var save = false
     private var restart = false
     private var callVolume = BaresipService.callVolume
+    private var oldMicGain = ""
     private var oldAudioModules = mutableMapOf<String, Boolean>()
     private var oldOpusBitrate = ""
     private var oldOpusPacketLoss = ""
@@ -74,6 +76,10 @@ class AudioActivity : AppCompatActivity() {
             }
         }
 
+        micGain = binding.MicGain
+        oldMicGain = Config.variable("augain")
+        micGain.setText(oldMicGain)
+
         speakerPhone = binding.SpeakerPhone
         speakerPhone.isChecked = BaresipService.speakerPhone
 
@@ -126,7 +132,7 @@ class AudioActivity : AppCompatActivity() {
         aec.isChecked = oldAec
 
         audioDelay = binding.AudioDelay
-        audioDelay.setText(BaresipService.audioDelay.toString())
+        audioDelay.setText("${BaresipService.audioDelay}")
 
         val toneCountrySpinner = binding.ToneCountrySpinner
         val toneCountryKeys = arrayListOf("bg", "br", "de", "cz", "es", "fi", "fr", "uk", "jp", "no", "nz", "se", "ru", "us")
@@ -179,6 +185,36 @@ class AudioActivity : AppCompatActivity() {
                     save = true
                 }
 
+                var gain = micGain.text.toString().trim()
+                if (!gain.contains("."))
+                    gain = "$gain.0"
+                if (gain != oldMicGain) {
+                    if (!checkMicGain(gain)) {
+                        Utils.alertView(this, getString(R.string.notice),
+                            "${getString(R.string.invalid_microphone_gain)}: $gain.")
+                        micGain.setText(oldMicGain)
+                        return false
+                    }
+                    if (gain == "1.0") {
+                        Api.module_unload("augain")
+                        Config.removeVariableValue("module", "augain.so")
+                        Config.replaceVariable("augain", "1.0")
+                    } else {
+                        if (oldMicGain == "1.0") {
+                            if (Api.module_load("augain") != 0) {
+                                Utils.alertView(this, getString(R.string.error),
+                                    getString(R.string.failed_to_load_module))
+                                micGain.setText(oldMicGain)
+                                return false
+                            }
+                            Config.addVariable("module", "augain.so")
+                        }
+                        Config.replaceVariable("augain", gain)
+                        Api.cmd_exec("augain $gain")
+                    }
+                    save = true
+                }
+
                 if (speakerPhone.isChecked != BaresipService.speakerPhone) {
                     BaresipService.speakerPhone = speakerPhone.isChecked
                     Config.replaceVariable("speaker_phone",
@@ -235,12 +271,16 @@ class AudioActivity : AppCompatActivity() {
 
                 if (aec.isChecked != oldAec) {
                     if (aec.isChecked) {
-                        Config.replaceVariable("module", "webrtc_aecm.so")
-                        if (Api.module_load("webrtc_aecm.so") != 0) {
-                            Utils.alertView(this, getString(R.string.error),
+                        Config.addVariable("module", "webrtc_aecm.so")
+                        if (gain != "1.0") {
+                            restart = true
+                        } else {
+                            if (Api.module_load("webrtc_aecm.so") != 0) {
+                                Utils.alertView(this, getString(R.string.error),
                                     getString(R.string.failed_to_load_module))
-                            aec.isChecked = false
-                            return false
+                                aec.isChecked = false
+                                return false
+                            }
                         }
                     } else {
                         Api.module_unload("webrtc_aecm.so")
@@ -298,6 +338,11 @@ class AudioActivity : AppCompatActivity() {
             Utils.alertView(this, getString(R.string.default_call_volume),
                     getString(R.string.default_call_volume_help))
         }
+        binding.MicGainTitle.setOnClickListener {
+            Utils.alertView(this, getString(R.string.microphone_gain),
+                getString(R.string.microphone_gain_help)
+            )
+        }
         binding.SpeakerPhoneTitle.setOnClickListener {
             Utils.alertView(this, getString(R.string.speaker_phone),
                 getString(R.string.speaker_phone_help))
@@ -328,6 +373,16 @@ class AudioActivity : AppCompatActivity() {
         }
     }
 
+    private fun checkMicGain(micGain: String): Boolean {
+        val number =
+            try {
+                micGain.toDouble()
+            } catch (e: NumberFormatException) {
+                return false
+            }
+        return number >= 1.0
+    }
+
     private fun checkOpusBitRate(opusBitRate: String): Boolean {
         val number = opusBitRate.toIntOrNull() ?: return false
         return (number >= 6000) && (number <= 510000)
diff --git a/app/src/main/kotlin/com/tutpro/baresip/Config.kt b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
index 78766c9e..efe6feaa 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/Config.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
@@ -157,6 +157,12 @@ object Config {
         if ("webrtc_aecm.so" in previousModules)
             config = "${config}module webrtc_aecm.so\n"
 
+        val micGain = previousVariable("augain")
+        config = if (micGain == ""  || micGain == "1.0")
+            "${config}augain 1.0\n"
+        else
+            "${config}module augain.so\naugain $micGain\n"
+
         val opusBitRate = previousVariable("opus_bitrate")
         config = if (opusBitRate == "")
             "${config}opus_bitrate 28000\n"
diff --git a/app/src/main/res/layout/activity_audio.xml b/app/src/main/res/layout/activity_audio.xml
index d5941e79..df47cf96 100644
--- a/app/src/main/res/layout/activity_audio.xml
+++ b/app/src/main/res/layout/activity_audio.xml
@@ -40,6 +40,36 @@
             </Spinner>
         </RelativeLayout>
 
+        <RelativeLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="0dp"
+            android:orientation="horizontal" >
+            <TextView
+                android:id="@+id/MicGainTitle"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_alignParentStart="true"
+                android:layout_centerVertical="true"
+                android:textSize="18sp"
+                android:text="@string/microphone_gain" >
+            </TextView>
+            <EditText
+                android:id="@+id/MicGain"
+                android:layout_height="wrap_content"
+                android:layout_width="fill_parent"
+                android:layout_centerVertical="true"
+                android:layout_toEndOf="@+id/MicGainTitle"
+                android:layout_marginStart="10dp"
+                android:textSize="18sp"
+                android:scrollHorizontally="true"
+                android:inputType="numberDecimal"
+                android:hint="@string/_1.0"
+                android:textColorHint="@color/colorSecondaryDark"
+                android:importantForAutofill="no" >
+            </EditText>
+        </RelativeLayout>
+
         <RelativeLayout
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
diff --git a/app/src/main/res/values-fi/strings.xml b/app/src/main/res/values-fi/strings.xml
index 76cfe722..339d2392 100644
--- a/app/src/main/res/values-fi/strings.xml
+++ b/app/src/main/res/values-fi/strings.xml
@@ -370,6 +370,12 @@
     <string name="aec_extended_filter_help">Jos merkitty, kaiun poistossa käytetään laajennettua
         suodatinta.
     </string>
+    <string name="microphone_gain">Mikrofonin äänikerroin</string>
+    <string name="microphone_gain_help">Kertoo mikrofonin äänen voimakkuuden tällä desimaaliluvulla.
+        Minimikerroin on 1.0 (tehdasasetus), mikä ei muuta mikrofonin äänen voimakkuutta.  Suuremmat
+        arvot voivat vaikuttaa negatiivisesti äänen laatuun.</string>
+    <string name="invalid_microphone_gain">Virheellinen mikrofonin äänikerroin</string>
+    <string name="_1.0" translatable="false">1.0</string>
     <string name="opus_bit_rate">Opus-koodekin bittinopeus</string>
     <string name="opus_bit_rate_help">Opus-koodekin käyttämä
     keskimääräinen enimmäisnopeus. Mahdollisia arvoja ovat
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 5eb46d60..f61f702a 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -344,6 +344,12 @@
     <string name="aec_help">If checked, echo cancellation is attempted on call audio.</string>
     <string name="aec_extended_filter">AEC Extended Filter</string>
     <string name="aec_extended_filter_help">If checked, echo cancellation is using extended filter.</string>
+    <string name="microphone_gain">Microphone Gain</string>
+    <string name="microphone_gain_help">Multiply microphone volume by this decimal number.  Minimum
+        value is 1.0 (factory default) that disables microphone gain. Larger values may negatively
+        affect audio quality.</string>
+    <string name="invalid_microphone_gain">Invalid Microphone Gain value</string>
+    <string name="_1.0" translatable="false">1.0</string>
     <string name="opus_bit_rate">Opus Bit Rate</string>
     <string name="opus_bit_rate_help">Average maximum bit rate used by Opus audio stream.
         Valid values are 6000-510000. Factory default is 28000.</string>