The Reserve Bank says it is prepared to cut the cash rate further if needed to improve economic conditions in Australia.
RBA governor Philip Lowe on Tuesday delivered the Sir Leslie Melville lecture in Canberra - a tribute to the late former RBA board member between 1960 and 1975.
The RBA has lowered interest rates three times over the year to a record low 0.75 per cent.
The next board meeting and rate decision is due on November 5.
"We are confident that these reductions are helping the Australian economy and supporting the gentle turning point in economic growth," Dr Lowe said.
"In doing so, low interest rates are supporting jobs and overall income growth."
But he acknowledged monetary policy was not working in the same way it used to.
"We also recognise that low interest rates hurt the finances of many people, particularly those relying on interest income. So there is a balancing act here," he said.
"The board is prepared to ease monetary policy further if needed.
"Having said that, it is extraordinarily unlikely that we will see negative interest rates in Australia.
"It is likely though that we will require an extended period of low interest rates to reach full employment and for inflation to be consistent with the target."
The RBA's focus was on improving the investment environment in Australia so investors use low funding costs to build new productive assets, he said.
He said there were factors in the hands of business and government which could also improve the investment climate, such as reducing geopolitical tensions and providing "structural measures that give people greater confidence about future economic growth, so that they are prepared to expand, invest and innovate".
Global stresses were of particular concern, including trade and technology disputes between China and the United States, Brexit, the ongoing tensions in the Middle East and the problems in Hong Kong.
Australian Associated Press