First, we need to determine the capacity of the small bin. Since the small bin can hold three-fourths the volume of a large bin, we calculate:
\[ \text{Capacity of the small bin} = \frac{3}{4} \times 44 = \frac{132}{4} = 33 \text{ towels} \]
Next, we know that 17 towels have already been placed in the small bin. To find out how many more towels can be stored, we subtract the number of towels already in the small bin from its total capacity:
\[ \text{Remaining capacity} = \text{Capacity of the small bin} - \text{Towels already in the small bin} = 33 - 17 = 16 \text{ towels} \]
Therefore, the number of additional towels that can be stored in the small bin is
\[ \boxed{16}. \]