Madeleine Easton said nurses had phoned the Dunedin City Council noise control staff on "numerous occasions", but council records showed the last complaint was made in February this year.
Council environmental team leader Ros MacGill said on that occasion the noise level was low.
In February last year, four complaints had resulted in verbal warnings.
It was thought the situation had improved because complaints were not being made.
The council had asked hospital authorities to encourage staff to phone at the time they were concerned about noise so it could be investigated.
It was hard to investigate a couple of days after an event.
Mrs Easton said patients who might have spent six to eight hours on the operating table and who might be lying awake worrying whether all their cancer had been removed, or who were receiving palliative care, did not need "that constant drumming all night long".
On a recent Saturday night, Mrs Easton said she had wondered why patients were up making cups of tea at 2am.
"They said: 'We can't sleep. Listen to that noise'."
Although she worked in a surgical ward, she had heard people complain about the noise in other areas, including intensive care.
Tavern general manager Mark Deason was surprised at the complaint.
He said he could only recall one visit from noise control officers this year and two the previous year.
The tavern advised people to contact them directly by phone if they had a concern about noise.
He had not received any calls from the hospital since last year.
"We don't want people to be suffering and not able to sleep."
Sometimes, complaints had occurred when new disc jockeys were in training - "they get a bit enthusiastic".
On occasions, depending on the stillness of the night, the noise might appear to be coming from the tavern, but could be emanating from the Captain Cook Tavern or events at the University of Otago.
The tavern had hoped to do some structural alterations which would have included extra sound proofing but, after preliminary investigations more than a year ago, ruled it out because of the cost of complying with the red tape involved. If it was considered there was a problem the tavern could look at extra insulation or other measures which might help, he said.
Mrs Easton raised her concerns at the Dunedin City Council annual plan hearings this week, suggesting licensing hours should not have been extended beyond midnight.
