Measures for the accuracy of speech transmission over an audio channel, such as Speech Transmission Index, rely on random word recognition as the standard for quality. In this paper, we propose that the ability to recall information at a later time is a more useful standard for sound quality than simply recognizing words. Recall, particularly in a complex or noisy environment, depends critically on the focused attention of a listener. There is evidence that “proximity,” the auditory perception that a source is close to a listener, enhances both focused attention and the ability to localize and separate sound sources from competing signals. We find that proximity and the benefits it brings depend on the phase alignment of frequencies above 1000 Hz. This alignment is lost when there are excess reflections, reverberation, noise, or multiple loudspeakers. We will present measurement techniques that can quantify proximity from an impulse response, and sound designs that maximize it in practice.