Development and validation of a novel tool for assessingpitch discriminationIssei Ichimiya*, Hiroko IchimiyaIchimiya Clinic, 665-787 Oh’aza Kitsuki, Kitsuki City, Oita 873-0001, Japan1. IntroductionSeveral investigators have evaluated the pitch discriminationability of the human brain using psychoacoustic tasks. Thejudgment of a higher or lower pitch for two tones, known aspitch direction discrimination (PDirD), is controlled by the rightauditory cortex [1,2]. On the other hand, it is suggested that theright auditory cortex is not involved in pitch difference discrimi-nation (PDiffD), which is the judgment of same or different pitchesfor two tones [1]. PDiffD is a simpler judgment that does notrequire sequential analysis and perception of the relative pitch.Therefore, it is speculated that PDirD involves a higher orderperceptual phenomena compared with PDiffD.Few studies have analyzed the relationship between pitchdiscrimination and hearing impairment. Nelson and Freyman [3]assessed patients with sensorineural hearing loss and showed thatthe ability to differentiate pitch limens was frequently poor.However, in their study, all subjects were well trained in pitchdiscrimination tasks before participation. PDirD has been shown tobe sensitive to the effects of learning through musical andpsychoacoustic training, particularly in individuals with little orno musical training [4]. Therefore, it is speculated that the trainingtask used by Nelson and Freyman was necessary to yieldappropriate results. However, such training tasks are timeconsuming and difficult to apply to patients in daily clinicalpractice. This is probably one reason why the pitch discriminationabilities of subjects with hearing impairment are not well studied.The purpose of the present study was to develop and validate atool for the assessment of pitch discrimination that can be easilyapplied in otolaryngology clinics, keeping in mind that it should befeasible to perform in addition to routine audiometry, should notrequire prior specific training, and should show little individualvariations. In addition, it should not be a time-consumingexamination. Accordingly, subjects with normal hearing weremade to perform PDiffD and PDirD tasks. They also performed anewly developed task that we named pitch pattern detection(PPD), wherein they detected pitch differences by judging thepattern of a tone complex. The obtained threshold values wereAuris Nasus Larynx xxx (2015) xxx–xxxA R T I C L E I N F OArticle history:Received 25 May 2015Accepted 15 July 2015Available online xxxKeywords:Parameter Estimation by Sequential TestingPitch difference discriminationPitch direction discriminationPitch pattern detectionPsychoacousticsA B S T R A C TObjective: To develop and validate a tool for pitch discrimination that can be easily applied inotolaryngology clinics.Methods: Twenty healthy subjects performed three psychoacoustic tasks for assessing pitchdiscrimination thresholds, which were compared among the three tasks. In the pitch directiondiscrimination (PDirD) task, the subjects judged the pitch of two tones as higher or lower. In the pitchdifference discrimination (PDiffD) task, the subjects judged the pitch of two tones as same or different. Inthe pitch pattern detection (PPD) task, the subjects judged the pattern of a tone complex. Using tone setsfrom level 0 to level 8, pitch thresholds were determined using the Parameter Estimation by SequentialTesting (PEST) staircase procedure. The tasks were performed without prior training.Results: Every test was performed twice for each ear, and the better results were adopted as thethreshold values. The PDirD thresholds varied considerably among the subjects and showed significantlylarger deviations relative to those of the PPD thresholds. The number of below 0 thresholds, which areconsidered inadequate results, was significantly larger in the PDiffD task. In the PPD task, all thresholdsexcept one were above level 6. The average total time taken to complete the PPD task was 7.7 min, whichwas significantly lesser than that taken to complete the other two tasks.Conclusion: The results of our study suggest that the PPD task is a reliable and easily available tool for theassessment of pitch discrimination.? 2015 Elsevier Ireland Ltd. All rights reserved.* Corresponding author. Tel.: +81 978 62 1233; fax: +81 978 62 1233.E-mail address: ich-oit@umin.ac.jp (I. Ichimiya).G ModelANL-2004; No. of Pages 6Please cite this article in press as: Ichimiya I, Ichimiya H. Development and validation of a novel tool for assessing pitch discrimination.Auris Nasus Larynx (2015), http://dx.doi.org/10.1016/j.anl.2015.07.002Contents lists available at ScienceDirectAuris Nasus Larynxjo u rn al h om epag e: ww w.els evier.c o m/lo cat e/anlhttp://dx.doi.org/10.1016/j.anl.2015.07.0020385-8146/? 2015 Elsevier Ireland Ltd. All rights reserved.
