Louise, without a photo or more information, I can only make general guesses....

A quick search tells me most soil in RI is acidic and rocky, with exceptions of course, and yours could be one of the exceptions. But PH too high, or not enough acidity, would most likely present as pale green to yellow leaves with darker veins. The fact that at least one of your azaleas blooms would indicate enough light.

Azaleas grow best in soil that is high in organic content that stays moist but doesn't remain soggy. Exposure to harsh freezing winds in winter, or drying winds without adequate water in summer and fall could lead to sparse and brownish leaves. Are your plants mulched with something organic (I top dress my own with compost, available by the bag if you haven't made your own), helps with nutrition, cools roots, conserves moisture.

The areas of RI I have visited were sandy. Sand is well drained but it doesn't hold water and nutrients well. I like adding peat mulch to the soil to increase the humus content. Also the addition of clay or top soil will have a good impact. Clay is actually a good soil IF it drains properly. If your soil is sandy, some clay will help it.

I doubt that acidity is the problem. When that is the problem the leaves turn yellow with green veins. It is very easy to spot and is easy to correct with powdered sulfur. Do not use aluminum sulfate. It kills rhododendrons and azaleas.

If the leaves don't have a good green color to them, it can be a nitrogen or magnesium deficiency. Using a good azalea fertilizer like Hollytone once each year can help that. I recommend using once each year at half the rate on the package. Also, magnesium sulfate, Epsom salts, may help.

Yellowing of leaves surfaces, often with brownish burned areas, occurring on leaves that are more exposed to sun, is caused by more sun exposure than the plant is able to tolerate. Some varieties need shade, while all plants that have been protected from direct sun will be tender until hardened off by gradual exposure to sun light. Possible solutions are to give the plant more shade or move it to a more protected site.

I assume you are talking about evergreen azaleas. They are not terribly hardy and often show winter damage on their leaves. They actually have two flushes of growth each year. The first flush is in the spring. Then in summer they get another flush of growth. If there is dry weather during either flush of growth, the leave will look misshapen.

Here is a link that might be useful: How to grow azaleas.