Musical note recognition based on the upper adjacent harmonics without the presence of the fundamental frequency

Abstract

Musical signals are complex periodic waveforms characterized by the sum of different frequencies. In a harmonic complex tone, the lowest frequency is called fundamental frequency (f0), while the other frequencies are called harmonics, and their frequencies are integer multiples of the fundamental. The perceived pitch of a sound is correlated with the fundamental frequency, even though it may be impossible to hear f0 in many situations. In these cases, it is possible to identify the pitch based on the upper consecutive harmonics. This study aimed to evaluate the identification of the notes based on the presence of consecutive harmonics only and to determine the importance of their distance from the fundamental frequency. The study was carried out on 30 normally hearing amateur musicians without perfect pitch. The acoustic signal was characterized by the association of four consecutive and two consecutive harmonics of the middle region notes of the piano keyboard. The correct identification rate ranged between 8 and 100%, with better identification occurring when more harmonics and lower frequencies were present. The results confirm that it is possible to identify a note solely based on the presence of harmonics near the fundamental frequency, especially if it is under 2000 Hz.

Keywords: Fundamental note; Harmonics; Musical note identification; Pitch.

Fig. 1

Rate of correct identification of the note in relationship to the frequency of the lowest harmonic presented. The numbers in the brackets refer to the frequency of the first harmonic.