More than half of Americans don't know how rising interest rates will affect their retirement and other investment accounts, according to a survey by financial services firm Edward Jones released Wednesday.

Sixty-three percent of Americans don’t know how rising interest rates will impact investment portfolios, such as 401(k)s, IRAs and other savings platforms, says the survey of 1,008 people.

Edward Jones says investors need to know about the impact of interest rates because bond prices typically move inversely to interest rates. Higher interest rates mean higher current income for an investor purchasing new bonds. For investors who already own a significant amount of fixed income, rising rates and corresponding falling bond values may mean lower overall portfolio value. Short-term bonds, while offering lower income opportunities, are less impacted by the drop in bond value that is seen in long-term investments.

“While it’s hard to know exactly where interest rates will go in the coming weeks and months, we believe over the long term that rates will continue to rise," says Tom Kersting, fixed-income strategist at Edward Jones. “Fixed income is still an important part of an overall investment portfolio, but we want to remind investors that now is the time to consider buying short- and intermediate-term bonds, rather than just long-term bonds.”

Understanding the impact of interest rates increases with age, the survey says. For those respondents ages 18 to 34, 22 percent say they understand the relationship between bonds and interest rates. That number goes to 28 percent for the next age group (35 to 44 years of age) and is 37 percent for the 45 to 54 age range. It increases further to 41 percent for the 55 to 64 year olds and then dips slightly to 35 percent for those 65 and older, the survey says.

Income also plays a role in understanding the relationship between higher rates and investments. For those in the lowest income bracket, $35,000 a year or less, 35 percent say they don't understand the impact of rising rates, while only 13 percent of those with incomes of $100,000 say they don't understand the impact.