The front-row seats in an auditorium are 10.4 m from a loudspeaker (circular aperture: 24.4 cm) on stage. The seats are placed every 0.75 m (with the middle seat centered in front of the loudspeaker). In what seat nearest the middle seat of the row (on either side) will it be most difficult to hear a tone of 3430 Hz from the speaker? [The speed of sound in 20°C air is 343 m/s.]