(3) And lastly, an individual had to be a member of a musical organization or group either currently or in the past. Such groups ranged from middle and high school concert and marching bands to Purdue University musical groups. These criteria were designed to select Epacadostat individuals who had significantly more musical training than an average non-musician while not reaching the level of professional musicians. All musicians received training for more than one instrument.

Four listed voice as one of their expertise areas, but none of the musicians trained in voice exclusively. Additionally, none of the musicians listed either a cello or a French Horn (whose sounds were used as stimuli in the current study) as their primary or secondary instruments of training. Stimuli consisted of two sound categories – human voices and musical instruments. The voice category contained natural recordings of a male and a female voice saying a neutral sound Selleck GSK-J4 [a]. The musical instruments category contained natural recordings of a cello and a French Horn playing an F3 note. Both types of stimuli were equated in frequency (174 Hz), which remained constant for the duration of the sound. This was achieved by asking speakers to match the pitch of a pre-recorded tone. Speakers were successful within a few hertz. The remaining frequency difference was corrected in Praat 5.1

(Boersma & Weenink, 2011). Each sound had two durations – 350 and 550 ms. The short duration sound was created by reducing the length of all parts of the long duration sound in Praat 5.1. Spectrally-rotated versions of all sounds were generated by rotating their frequencies around 2000 Hz (MATLAB R2010b). Spectrally-rotated sounds retained their complexity,

pitch, periodicity and the overall temporal envelope as can be seen in their waveforms and spectrograms shown in Fig. 1. However, the timbre of original sounds was completely altered and no longer resembled any of the naturally produced sounds (Blesser, 1972). To account for differences in perceptual loudness, the male and female voice stimuli were presented at 70 dB SPL, and the cello and the French Horn stimuli at 73 and 74 dB SPL, respectively. These values were selected during a pilot study in which participants were asked to judge whether the four sounds (male voice, female voice, eltoprazine cello, French Horn) sounded equally loud. The intensity of spectrally-rotated sounds was matched with that of their natural counterparts. Sounds were presented in free field via a single speaker (SONY) located approximately 1.2 m in front of a participant and directly above the computer monitor that displayed instructions and a hair-cross point for eye fixation. We used the auditory distraction paradigm developed by Schröger & Wolff (1998, 2000). The study had two conditions, with four blocks in each. The first condition consisted of naturally recorded (NAT) sounds, and the second condition of spectrally-rotated (ROT) sounds.