Towards a Vocal and Acoustic Description of Kapa Haka.

OBJECTIVE: The purpose of this study is to analyze the voice used in kapa haka, a contemporary indigenous vocal performance from New Zealand, which includes the well-known haka. This is the first study of its kind and is a preliminary investigation into the vocal and acoustic description of kapa haka. A significant goal of this study is to contribute ideas and potential definitions of vocal qualities to the community of kapa haka trainers that were specific to the genre. This strengths-based project raises up these vocal practices as legitimate and authentic colors within a vocal tradition that has seen generational learning disrupted by colonial interventions and is now flourishing within the community. METHODS: Eight kapa haka performers (three females, five males) were involved in the study, they were all experienced performers; furthermore, two had formal classical voice training. They were individually recorded speaking and performing three different genres of kapa haka (moteatea, waiata, and haka); all recordings were in te reo Maori (the Maori language). In addition, electroglottograph (EGG) signals were collected. An auditory-perceptual evaluation of the kapa haka voice was completed by three singer-researcher-pedagogues familiar with Western and non-western genres of singing. They all have experience appropriately collecting and analyzing data from indigenous communities, and they all understand the sociopolitical context of the vocal genre within the local colonial history. A specific evaluation instrument was created, and the results were validated. The acoustic and time-aligned EGG data was annotated at the phoneme level, and the signal analysis was performed in MATLAB. Averaged EGG pulses from /a/ segments were investigated, along with long-term average spectrums of the performances obtained from both the audio signal and the EGG signals. RESULTS: The perceptual analysis suggests the biggest difference in vocal styles was between the haka and the other two genres (and speech). The acoustic and EGG results support these findings. CONCLUSIONS: Common characteristics, perceptually and acoustically, were identified in the kapa haka performance styles across the eight performers.

Female adolescent singing voice characteristics: an exploratory study using LTAS and inverse filtering.

Background and Aim: To date, little research is available that objectively quantifies female adolescent singing-voice characteristics in light of the physiological and functional developments that occur from puberty to adulthood. This exploratory study sought to augment the pool of data available that offers objective voice analysis of female singers in late adolescence.Methods: Using long-term average spectra (LTAS) and inverse filtering techniques, dynamic range and voice-source characteristics were determined in a cohort of vocally healthy cis-gender female adolescent singers (17 to 19 years) from high-school choirs in Aotearoa New Zealand. Non-parametric statistics were used to determine associations and significant differences.Results: Wide intersubject variation was seen between dynamic range, spectral measures of harmonic organisation (formant cluster prominence, FCP), noise components in the spectrum (high-frequency energy ratio, HFER), and the normalised amplitude quotient (NAQ) suggesting great variability in ability to control phonatory mechanisms such as subglottal pressure (Psub), glottal configuration and adduction, and vocal tract shaping. A strong association between the HFER and NAQ suggest that these non-invasive measures may offer complimentary insights into vocal function, specifically with regard to glottal adduction and turbulent noise in the voice signal.Conclusion: Knowledge of the range of variation within healthy adolescent singers is necessary for the development of effective and inclusive pedagogical practices, and for vocal-health professionals working with singers of this age. LTAS and inverse filtering are useful non-invasive tools for determining such characteristics.

CPPS and Voice-Source Parameters: Objective Analysis of the Singing Voice.

INTRODUCTION: In recent years cepstral analysis and specific cepstrum-based measures such as smoothed cepstral peak prominence (CPPS) has become increasingly researched and utilized in attempts to determine the extent of overall dysphonia in voice signals. Yet, few studies have extensively examined how specific voice-source parameters affect CPPS values. OBJECTIVE: Using a range of synthesized tones, this exploratory study sought to systematically analyze the effect of fundamental frequency (fo), vibrato extent, source-spectrum tilt, and the amplitude of the voice-source fundamental on CPPS values. MATERIALS AND METHODS: A series of scales were synthesised using the freeware Madde. Fundamental frequency, vibrato extent, source-spectrum tilt, and the amplitude of the voice-source fundamental were systematically and independently varied. The tones were analysed in PRAAT, and statistical analyses were conducted in SPSS. RESULTS: CPPS was significantly affected by both fo and source-spectrum tilt, independently. A nonlinear association was seen between vibrato extent and CPPS, where CPPS values increased from 0 to 0.6 semitones (ST), then rapidly decreased approaching 1.0 ST. No relationship was seen between the amplitude of the voice-source fundamental and CPPS. CONCLUSION: The large effect of fo should be taken into account when analyzing the voice, particularly in singing-voice research, when comparing pre and posttreatment data, and when comparing inter-subject CPPS data.