|
 
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| ORIGINAL ARTICLE |
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| Year : 2022 | Volume
: 36
| Issue : 1 | Page : 1-6 |
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Vocal changes in different phases of menstrual cycle: An evidence from the acoustic, cepstral, and spectral analysis
SV Narasimhan1, M Pooja2
1 Department of Speech and Language Pathology, JSS Institute of Speech and Hearing, Mysore, Karnataka, India
2 Speech Language Pathologist and Audiologist, Sound Tree Speech and Hearing Clinic, Mysuru, Karnataka, India
| Date of Submission | 04-Feb-2022 |
| Date of Decision | 14-May-2022 |
| Date of Acceptance | 19-May-2022 |
| Date of Web Publication | 27-Jun-2022 |
Correspondence Address:
S V Narasimhan
Department of Speech and Language Pathology, JSS Institute of Speech and Hearing, Mysore, Karnataka
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jisha.jisha_5_22
Introduction: Spectral and cepstral analyses of voice have potential clinical implications and can be used as a quantitative acoustic index to assess vocal function in various phases of the menstrual cycle. However, only a handful of studies have attempted to investigate these measures to document the vocal changes across various phases of the menstrual cycle and the results are not conclusive. Therefore, the study aimed to document the acoustic, spectral, and cepstral parameters of voice across the four phases of the menstrual cycle. Methods: Phonation samples were recorded during four phases of the menstrual cycle –menstrual phase, follicular phase, ovulation phase, and luteal phase – from 30 female participants. None of the participants reported any hormone-related problems, presence, or history of any voice problems and had a regular menstrual cycle at least from the past 5 years. All the phonation samples were analyzed, and the acoustic, spectral, and cepstral parameters were extracted. Results: Fundamental frequency, H1-H2, and cepstral peak prominence (CPP) values were significantly different across the phases of the menstrual cycle. Across the phases of the menstrual cycle, the fundamental frequency, H1-H2, and the CPP values were optimal during the follicular phase and the deviant values were noted during the luteal phase of the menstrual cycle. Conclusion: Future investigations could include the analysis of cepstral and spectral parameters extracted from both the phonation and speech samples that can provide more penetrating and ample in-depth insights into the voice changes across the various phases of the menstrual cycle.
Keywords: Cepstral analysis, cepstral parameters, phases of menstrual cycle, spectral parameters, voice disorders
How to cite this article:
Narasimhan S V, Pooja M. Vocal changes in different phases of menstrual cycle: An evidence from the acoustic, cepstral, and spectral analysis. J Indian Speech Language Hearing Assoc 2022;36:1-6 |
How to cite this URL:
Narasimhan S V, Pooja M. Vocal changes in different phases of menstrual cycle: An evidence from the acoustic, cepstral, and spectral analysis. J Indian Speech Language Hearing Assoc [serial online] 2022 [cited 2023 Jan 30];36:1-6. Available from: https://www.jisha.org/text.asp?2022/36/1/1/348430 |
| Introduction | |  |
“The human larynx is a hormonal target organ.”[1] Vocal fold mucosa contains specific receptors of sex hormones. Hence, fluctuation in the sex hormones, especially estrogen and progesterone, influences the laryngeal function by altering the histology of the vocal fold and thereby affects voice production in females.[2],[3],[4] Thus, voice changes due to hormonal alterations are evident throughout the female life. Voice changes start right from puberty, followed by voice fluctuations during the reproductive years with the menstrual cycle and voice changes due to deterioration in hormonal activity after menopause.[2]
The menstrual cycle that occurs during the reproductive years is a naturally occurring event resulting from hormonal changes in the female body.[5] Each menstruation cycle occurs once in approximately 28 days. The reproductive menstrual cycle can be divided into four phases– the menstrual phase, the follicular phase, an ovulation phase, and the luteal phase. The sex hormones, especially estrogen and progesterone change during each phase of the menstrual cycle.[5] Changes in Estrogen levels result in increased capillary permeability and cause a proliferative and hypertrophic effect on the vocal fold mucosa.[6] On the other hand, the changes in progesterone levels decrease the capillary permeability, causing edema and dehydrating effects on the mucosa.[6] These fluctuations in the hormonal levels during various phases of a menstrual cycle can cause physiological changes in the vocal folds and result in altered voice quality.[6]
Besides focusing on the physiological changes in vocal folds tissues, earlier studies have also documented the perceptual changes in female voice during different phases of the menstrual cycle.[7],[8],[9] The studies have revealed that the attractiveness of the female voice changes during the phases of the menstruation cycle. The researchers have even documented the lowest and highest voice attractiveness ratings during the menstrual phase[8] and fertile phases[7],[9] of the menstrual cycle, respectively. Therefore, past studies have concluded that the vocal changes during the phases of a menstrual cycle can provide a valuable source of information identical to the data on women's fertility.
Several past studies have studied the acoustic changes in voice during the phases of the menstrual cycle and have provided mixed results. Some researchers have reported an increase in fundamental frequency or pitch in the luteal phase[10] and some have documented increased fundamental frequency in the follicular phase of the menstrual cycle.[11] Researchers have also found a decrease in the fundamental frequency of voice during the luteal phase.[7],[12] Other researchers have reported no significant differences in vocal pitch between the different phases of the menstrual cycle.[13],[14],[15]
The cepstral analysis is another popular tool and legitimate method used for the analysis of voice.[16],[17] The cepstral analysis measures the degree of harmonic organization in the voice, i.e., a prominent cepstral peak indicates a good harmonic structure in the voice.[18],[19],[20],[21] Several past studies have opined that the cepstral measures of voice rely upon the peak-to-peak average calculation and not on the estimation of the fundamental frequency for analysis.[21],[22],[23] Therefore, cepstral parameters of voice are more reliable and effective in voice analysis compared to traditional acoustic parameters. A recent study investigated the cepstral parameter of voice in various phases of the menstrual cycle and reported no significant differences in cepstral peak prominence (CPP) values between the various phases of the menstrual cycle.[24] Therefore, the study concluded that even though CPP has been considered a sensitive parameter to document the subtle vocal changes, the study results indicating that there were no differences in CPP between various phases of the menstrual cycle, were surprising.[24] However, studies have even reported that the cepstral parameters were capable to discriminate the voice samples of females with and with hormonal problems such as polycystic ovarian syndrome.[25]
Spectral analysis or the analysis of spectral tilt is another objective way of voice assessment. Earlier investigations have shown that the spectral analysis or analysis of vowel harmonic amplitude differences are reliable, robust, objective, and powerful markers of vocal function change.[26],[27] The differences between the first harmonic amplitude (H1) and the second harmonic amplitude (H2) indicate the extent of vocal fold tension during phonation.[28],[29] The difference between H1 and A1 (amplitude of the most robust harmonic in the region of first formant frequency), indicates the presence of a glottal gap during phonation. H1 and A2 (amplitude of the most robust harmonic in the region of second formant frequency) difference indicates the phonation contrasts between the mid-tone and low-tone.[30],[31] The difference between H1 and A3 (amplitude of the most robust harmonic in the region of third formant frequency) reflects the spectral tilt across higher frequencies.[30]
Even though the spectral and cepstral analysis has potential clinical implications and can be used as a quantitative acoustic index to assess vocal function in various phases of the menstrual cycle, only a handful of studies, have attempted to investigate these measures to document the vocal changes between various phases of menstrual cycle and the results are inconsistent. Therefore, the present study aimed to investigate the acoustic, spectral, and cepstral measures of voice across the four phases of the menstrual cycle – menstrual phase, follicular phase, ovulation phase, and the luteal phase.
| Methods | | |
Participants
The study included 30 female participants within the age range of 20–40 years (with a mean age of 32.4 ± 2.4 years). All the participants were formally evaluated by an experienced Speech Language Pathologist, a qualified otolaryngologist, and a gynecologist. A part of the voice evaluation template, developed by the American Speech and Hearing Association, that included the demographic details, informal assessments of vocal hygiene, vocal activities, and environmental issues was administered to all the participants. None of the participants reported any hormone-related problems, presence, or history of any voice problems and had a regular menstrual cycle at least from the past 5 years. All the participants were native Kannada language speakers and had normal hearing sensitivity.[32] Convenience sampling was used to select the participants for the study. Informed consent was obtained from all the participants.
Procedure
Data collection
A sustained phonation task was used to collect the data from participants. Phonation samples were recorded during four phases of the menstrual cycle from each participant. The first recording was carried out on the second or 3rd day of menstruation (Menstrual phase – Phase 1). The second recording was carried out on the 8th or 9th day of menstruation (Follicular phase – Phase 2). The third recording was carried out on the 14th or 15th day of menstruation (Ovulation phase – Phase 3), and the last recording was carried out on the 24 or 25 day of the menstrual cycle (Luteal phase– Phase 4). Voice samples of all the participants were recorded in a soundproof room. The participants were seated comfortably in a chair in front of a computer screen. Participants were instructed by the investigator to take a deep breath and phonate the vowel/a/on exhalation at their comfortable pitch and loudness. Three trials of phonation were recorded. Voice samples were recorded using a Sony IC Digital Recorder (ICD-P320) that was kept at a constant distance of 15 cm and at an angle of 45° from the mouth of the participant. The digital recorder was attached to a personal computer (HP Pavilion G4, intel I5 processor, 64 bit) installed with Praat software (version 5.3.23).[33] Voice recordings were sampled at the rate of 44,100 Hz and digitized at 16 bits/sample quantization. For each participant, the most stable of the three recordings of vowel phonation was used for the analysis.
Data analysis
Praat software was used to extract the acoustic and spectral parameters of voice from all the phonation samples. Acoustic parameters, namely mean fundamental frequency (Hz), and range of fundamental frequency (Hz) were extracted as a part of acoustic analysis. Samples were transformed into the frequency domain using Praat software, and the spectral slice was obtained. Thus, the intensity as a function of frequency was displayed in a spectrum. The spectral amplitudes of H1 (first harmonic), H2 (second harmonic), A1 (amplitude of harmonic in the first formant frequency region), A2 (amplitude of harmonic in the second formant frequency region), and A3 (amplitude of harmonic in the third formant frequency region) were identified from the spectral slice and the spectral tilt parameters, namely H1-H2, H1-A1, H1-A2, and H1-A3 were calculated.[27] Cepstral parameters in phonation and speech samples were displayed as a waveform using the software (Speech Tool), and the CPP and CPPs values in phonation were obtained using the Hillenbrand algorithm.[34],[35]
Statistical analysis
Values of all the parameters were statistically analyzed using SPSS software (IBM Corp. Released 2016. IBM SPSS Statistics for Windows, Version 24.0. Armonk, NY: IBM Corp). As a part of descriptive statistics, the mean and standard deviation was calculated for each parameter across the recordings collected during all four phases of the menstrual cycle. Repeated measures ANOVA was carried out to determine the significant differences among all the objective parameters (acoustic, spectral, and cepstral parameters) between four phases of the menstrual cycle. Pairwise comparisons were carried out to determine the significant difference in each parameter between the four phases of the menstrual cycle. Statistical analysis was carried out at a 95% confidence interval (an alpha level of 0.05).
| Results | | |
[Table 1] presents the result of the descriptive statistics for acoustic, spectral, and cepstral parameters between four phases of the menstrual cycle. Among the acoustical parameters, the fundamental frequency value was higher in phase 3 and the lowest value was observed in phase 4 compared to other phases of the menstrual cycle. The results of repeated measures ANOVA showed that there was a significant difference (F (3, 87) =4.43, P = 0.01) in fundamental frequency between the four phases of the menstrual cycle. Pairwise comparison showed that there were significant differences in fundamental frequency values between phase 4 and phase 1; phase 4 and phase 2; phase 4 and phase 3. However, no significant difference was observed between phase 1, phase 2, and phase 3. However, the range of fundamental frequency values was highest for phase 4 and the lowest value was observed for phase 3. It was also noted that the standard deviation values of the fundamental frequency range were higher in phase 1 and phase 4, indicating poor phonatory stability in the luteal and menstrual phases. The results of repeated measures ANOVA showed that there were no significant differences noted in the range of fundamental frequency between the four phases of the menstrual cycle. Thus, it was inferred that, out of the two acoustic parameters, only the fundamental frequency values showed a significant difference between the phases of the menstrual cycle. Fundamental frequency in phase 4 (luteal phase) was significantly lower and phase 3 (ovulation phase) was significantly higher compared to all the other phases of the menstrual cycle. | Table 1: Mean and standard deviation of acoustic, spectral, and cepstral parameters across the four phases of the menstrual cycle
Click here to view |
Among the spectral parameters, the highest values were observed for phase 4 for all four spectral parameters, i.e., H1-H2, H1-A1, H1-A2, and H1-A3. The lowest values of H1-H2, H1-A1, and H1-A2 were observed in phase 3 of the menstrual cycle. The lowest value of H1-A3 was noted across phase 1 of the menstrual cycle. The result of repeated measures ANOVA revealed significant differences between phases of the menstrual cycle only across H1-H2 (F (3, 87) =2.69, P = 0.05). It was noted that H1-H2 in phase 4 of the menstrual cycle was significantly higher and H1-H2 in phase 2 was significantly lower compared to H1-H2 values in other phases of the menstrual cycle. The other spectral parameters-H1-A1, H1-A2, and H1-A3 showed no significant differences across phases of the menstrual cycle.
Among the cepstral parameters, CPP values were higher in phase 2 and the lowest values were observed in Phase 4, as evidenced from [Table 1]. Results of inferential statistics using repeated measures ANOVA showed that there was a significant difference in CPP values (F (3, 87) =6.26, P = 0.00) between four phases of the menstrual cycle. The pairwise comparison of CPP values revealed that the CPP values in phase 4 were significantly lower and values in phase 2 were significantly higher compared to the other phases of the menstrual cycle. Across CPPs values, even though the highest CPPs values were found in Phase 1 of the menstrual cycle, the results of inferential statistics revealed that there was no significant difference in CPPs values between the phases of the menstrual cycle.
| Discussion | | |
The study aimed at investigating the acoustic, spectral, and cepstral measures of voice across the four phases of the menstrual cycle - menstrual phase, follicular phase, ovulation phase, and luteal phase in women without voice problems and hormonal disturbances. The results showed that among the acoustic parameters, the fundamental frequency was significantly different across the four phases of the menstrual cycle. It was also found that the fundamental frequency in the luteal phase (phase 4) was significantly lower compared to all the other phases of the menstrual cycle. The acoustic findings of the present study were in line with the earlier studies reporting an increase in fundamental frequency or pitch in the luteal phase.[10]
The literature review shows inconsistent results, especially regarding the findings on the fundamental frequency. Some researchers have documented increased fundamental frequency in the follicular phase of the menstrual cycle,[11] whereas some studies have found a decrease in the fundamental frequency of voice during the luteal phase.[7],[12] Other researchers have reported no significant differences in vocal pitch between the different phases of the menstruation cycle.[13],[14],[15] These differences between the results of the present and past studies could be attributed to the disparities in methodological aspects between the studies. First, the method used to identify the phases of the menstrual cycle varies widely across the studies. Most of the studies have used cycle counting methods based on the participants' self-reports and others have used methods such as measuring body temperature, direct assessment of hormonal levels, or luteinizing hormone surge. Second, some studies have considered a smaller sample size which often results in a lack of statistical power to identify the voice changes.
Across the spectral parameters, only H1-H2 showed significant differences between phases of the menstrual cycle. It was noted that H1-H2 in the luteal phase of the menstrual cycle was significantly higher compared to H1-H2 values in other phases of the menstrual cycle. H1-H2 reflects the length of the glottal pulse opening phase during the vocal fold vibration[26] and a higher H1-H2 value indicates the tightness of the vocal fold.[36] As significantly higher H1-H2 was found during the luteal phase, it was inferred that phonation during the luteal phase may be characterized by a higher open quotient and high transglottal airflow. It was also noted that H1-H2 values were significantly lower in the follicular phase of the menstrual cycle. Thus, it was inferred that the glottal opening period was optimal and vocal fold vibration was more periodic during the follicular phase of the menstrual cycle.
Across the cepstral parameters, CPP values were noted to be significantly different between the four phases of the menstrual cycle. The CPP values in the luteal phase were significantly lower and CPP values in the follicular phase were significantly higher compared to other phases of the menstrual cycle. Voices with well-defined and good harmonic organization show prominent cepstral peaks and higher CPP values. Whereas, voices with poor harmonic organization show lower cepstral peak values.[37],[38],[39],[40] Therefore, the decreased CPP values during the luteal phase of the menstrual cycle may reflect the altered pattern of vocal fold movement, resulting in aperiodicity of vocal fold vibration, and increased noise during voice production. It was also implied from the results of the cepstral analysis that the most optimal vocal fold vibration might be evidenced during the follicular phase of the menstrual cycle as the follicular phase showed the highest CPP values. Therefore, the results of the present study also reconfirm that the spectral and cepstral parameters are complementary and efficient tools in the assessment of voice.
Most importantly, the findings of the study revealed that the acoustic, cepstral, and spectral parameters of voice showed optimal values during the follicular phase and the deviant values were noted during the luteal phase of the menstrual cycle. Hormonal levels, especially estrogen and progesterone, change during the follicular and luteal phases. Estrogen is found to be at the highest level before ovulation, i.e., the follicular phase. Whereas, the progesterone level increases after ovulation, i.e., during the luteal phase.[6] Changes in estrogen levels result in increased capillary permeability and cause a proliferative and hypertrophic effect on the vocal fold mucosa.[6] Whereas, the changes in progesterone levels decrease the capillary permeability, causing edema and dehydrating effects on the mucosa.[6] Progesterone and estrogen act synergistically on the musculomucosal complex of vocal fold tissues.[6] As vocal fold vibrations are directly influenced by these fluctuations in the hormonal levels, optimal values of voice parameters might be evidenced during the follicular phase and deviant values might be evidenced during the luteal phase of the menstrual cycle.
The present study used cycle counting methods based on the participants' self-reports, to collect the data on the phases of the menstrual cycle. However, the direct assessment of hormonal levels or luteinizing hormone surge could have provided more supplementary data on the phases of the menstrual cycle. The present study failed to get the participants evaluated by a qualified endocrinologist and relied on the evaluation reports of a gynecologist and the participants' self-reports. Further, the present study analyzed only the phonation samples at four phases of the menstrual cycle. Analyzing the speech samples could have provided supplementary data on the variation of vocal parameters across the phases of the menstrual cycle. Nevertheless, the present study was a preliminary attempt to document the variations in the objective parameters, especially the cepstral and spectral measures of voice across the phases of the menstrual cycle. However, the results of the present study have to be interpreted with a caution that as hormonal variations are robust in women with normal fertility, the vocal changes observed in the present study may not be noticed before all menstrual cycles.
| Conclusion | | |
The study investigated the differences in the objective parameters, i.e., acoustic, cepstral, and spectral measures of voice across the four phases of the menstrual cycle – menstrual phase, follicular phase, ovulation phase, luteal phase – in women without voice problems. The results revealed that the fundamental frequency, H1-H2, and CPP showed significant differences between the phases of the menstrual cycle. Future investigations could include the analysis of cepstral and spectral parameters extracted from both the phonation and speech samples that can provide more penetrating and ample in-depth insights into the voice changes across the various phases of the menstrual cycle. Supplementary research on the relationship between hormonal levels and vocal parameters can provide better discrimination of voice changes in different phases of the menstrual cycle.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Table 1]
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