Attender

from WordNet (r) 3.0 (2006)

attender
    n 1: someone who listens attentively [syn: {hearer}, {listener},
         {auditor}, {attender}]
    2: someone who waits on or tends to or attends to the needs of
       another [syn: {attendant}, {attender}, {tender}]
    3: a person who is present and participates in a meeting; "he
       was a regular attender at department meetings"; "the
       gathering satisfied both organizers and attendees" [syn:
       {attendant}, {attender}, {attendee}, {meeter}]

from The Collaborative International Dictionary of English v.0.48

Attender \At*tend"er\, n.
   One who, or that which, attends.
   [1913 Webster]