diff --git a/cara/apps/calculator/model_generator.py b/cara/apps/calculator/model_generator.py
index 9b1d2ad4..1da57809 100644
--- a/cara/apps/calculator/model_generator.py
+++ b/cara/apps/calculator/model_generator.py
@@ -247,7 +247,8 @@ def model_from_form(form: FormData) -> models.ExposureModel:
     # of the infected and exposed occupants respectively.
     # I.e. (infected_activity, infected_expiration), (exposed_activity, exposed_expiration)
 
-    activity_dict = {'office': (('Seated', 'Talking'), ('Seated', 'Talking')),
+    activity_dict = {'office': (('Seated', 'Conversation'), ('Seated', 'Conversation')),
+                     'callcentre': (('Seated', 'Talking'), ('Seated', 'Talking')),
                      'training': (('Light exercise', 'Talking'), ('Seated', 'Whispering')),
                      'workshop': (('Light exercise', 'Talking'), ('Light exercise', 'Talking'))}
 
@@ -323,7 +324,7 @@ def baseline_raw_form_data():
     }
 
 
-ACTIVITY_TYPES = {'office', 'training', 'workshop'}
+ACTIVITY_TYPES = {'office', 'training', 'callcentre', 'workshop'}
 EVENT_TYPES = {'single_event', 'recurrent_event'}
 MECHANICAL_VENTILATION_TYPES = {'air_changes', 'air_supply', 'not-applicable'}
 MASK_TYPES = {'Type I', 'FFP2'}
diff --git a/cara/apps/calculator/templates/calculator.form.html.j2 b/cara/apps/calculator/templates/calculator.form.html.j2
index 83b0eb0c..9fd342bd 100644
--- a/cara/apps/calculator/templates/calculator.form.html.j2
+++ b/cara/apps/calculator/templates/calculator.form.html.j2
@@ -111,6 +111,7 @@
 
     Activity type: <select id="activity_type" name="activity_type">
                     <option value="office">Office/Meeting</option>
+                    <option value="callcentre">Call Centre</option>
                     <option value="workshop">Workshop</option>
                     <option value="training">Training</option>
                    </select><br>
@@ -206,8 +207,9 @@
   <b>Activity types:</b><br>
   The type of activity that includes both the infected and exposed persons:
   <ul>
-    <li>Office/Meeting = typical scenario all persons seated, talking.</li>
+    <li>Office/Meeting = typical scenario all persons seated, in conversation (talking 33% of the time, otherwise breathing normally).</li>
     <li>Workshop = assembly workshop environment, all persons doing light exercise, talking.</li>
+    <li>Call Centre = A conservative assumption for office spaces, assumes all occupants are seated and talking continuously.</li>
     <li>Training = one person (the trainer) standing, talking, all others seated, talking quietly (whispering). It is assumed the trainer is the infected person, for the worst case scenario.</li>
   </ul>
   <b>Activity breaks:</b><br>
diff --git a/cara/models.py b/cara/models.py
index 12f85c7c..ed2f3c83 100644
--- a/cara/models.py
+++ b/cara/models.py
@@ -172,7 +172,7 @@ class MultipleVentilation:
     @abstractmethod
     def air_exchange(self, room: Room, time: float) -> float:
         """
-        Returns the rate at which air is being exchanged in the given room 
+        Returns the rate at which air is being exchanged in the given room
         at a given time (in hours).
         """
         return sum([ventilation.air_exchange(room,time)
@@ -271,7 +271,7 @@ class AirChange(Ventilation):
     #: The interval in which the ventilation is operating.
     active: Interval
 
-    #: The rate (in h^-1) at which the ventilation exchanges all the air 
+    #: The rate (in h^-1) at which the ventilation exchanges all the air
     # of the room (when switched on)
     air_exch: float
 
@@ -375,8 +375,10 @@ class Expiration:
 
 
 Expiration.types = {
+    #added new profile - Conversation = weighting of 1/3rd talking, 2/3 breathing.
     'Breathing': Expiration((0.084, 0.009, 0.003, 0.002)),
     'Whispering': Expiration((0.11, 0.014, 0.004, 0.002)),
+    'Conversation': Expiration((0.135, 0.029, 0.004, 0.005)),
     'Talking': Expiration((0.236, 0.068, 0.007, 0.011)),
     'Unmodulated Vocalization': Expiration((0.751, 0.139, 0.0139, 0.059)),
     'Superspreading event': Expiration((np.inf, np.inf, np.inf, np.inf)),