Efficient error detection skills, as a primary competency for
the conductor/teacher, can be facilitated by developing advanced
aural perception abilities so that incoming auditory stimuli can
be sensed and perceived accurately. This study compares aural
perception to the visual perception process, theorizing that
attention to a particular auditory stream causes concurrent auditory streams to be perceived in a manner analogous to
peripheral vision, here termed "peripheral hearing."
Because error detection requires focusing on a single errant auditory stream from among many incoming streams, the primary
question was to determine the effect of this singular focus upon
the simultaneous perception of concurrent auditory streams. A
secondary purpose was to examine the effect that acquiring an
aural "template" of the stimulus had upon this perception.
Procedure
An aural test containing three-line printed scores of short musical excerpts was administered to 178 undergraduate
instrumental music majors from eight colleges and universities,
who indicated errors or departures from the printed scores made by
a recorded ensemble. Subjects' focus was directed to a specific musical line, and maintained on that line by the insertion of
obvious errors on several excerpts, whereupon a concurrent line
was simultaneously deleted. Detection of the deleted musical line
was measured to indicate the extent of peripheral hearing.
To measure the effect that an aural template of the test familiarization procedure with a recorded piece of music. Half of the test excerpts were drawn from this piece (internal aural template piece) and half were drawn from unfamiliar (non-template)
music.

Conclusions
1. When aural focus was directed to one musical line through instruction and/or the insertion of an error as a "focus
re-inforcer," accuracy of perception in concurrent parts was
reduced significantly.
2. Perception within all areas of test items drawn from music for which subjects possessed an internal aural template was
significantly more accurate.
3. Detection of an alteration to a peripheral musical part was highest when the part was the melody and next highest when it
was the bass line.
4. The lower percentage of deleted parts detected compared to the percentage of focus re-inforcers detected suggests a possible
hierarchy of detectability among types of errors and
discrepancies.