# Do We Get What We Need from Clinical Acoustic Voice Measurements?
## 2 Background: Current State of the Art and Challenges in Clinical Acoustic Measurements
### Technical Challenges
\begin{table}
\begin{tabular}{|p{56.9 pt}|p{56.9 pt}|p{56.9 pt}|p{56.9 pt}|p{56.9 pt}|p{56.9 pt}|p{56.9 pt}|} \hline  & **General Description** & **Parameters with Specification Recommendations** & **Recording Equipment Equipment Equipment and File** & **Vocal Tasks** \\ \hline [PERSON] (1995) & \(\bullet\) Summary statement of expert panel regarding standardization and utility of voice perturbation methods. & \(\bullet\) Fundamental frequency (\(f_{0}\)) and amplitude (SPL) & \(\bullet\) & 16-bit A/C converter or DAT recorder & \(\bullet\) & Sustained vowels [a], [i], and comfortable, high, and low pitch and medium, soft, and loud intensity levels \\ \multirow{4}{*}{\(\bullet\)} & Review based detailed technical guidelines with classification scheme for voice recordings after signal quality and suitability for analysis methods (Types 1 to 3). & \(\bullet\) Perturbation parameters jitter and shimmer in more signal quality and suitability for signals & Sampling frequencies 20–100 kHz & \(\bullet\) Multiplex tokens of sustained vowels (10\(\times\)) \\ \cline{2-6}  & Short average cyclic parameter contour (\(f_{0}\) & \(\bullet\)) The spectral and SPL’s) in Type 1 and 2 signals & \(\bullet\) Sound-treated room with ambient noise \(<\) 50 dB & \(\bullet\) Uterances with induced \(f_{0}\) glides and intensity glides \\ \cline{2-6}  & & Spectrographic and perceptual analysis in irregular or aperiodic Type 3 signals & \(\bullet\) Control of room reverberation & \(\bullet\) Maximum phonation time [s] and [z] \\ \multirow{4}{*}{\(\bullet\)} & Recommends assessment of \(f_{0}\), SPL and voice quality for inter- and intra-subject comparisons & \(\bullet\) File formats: specific formats developed for scientific purposes or.wav files & \(\bullet\) Counting 1 to 100 at comfortable pitch and loudness \\ \cline{2-6}  & & & & \(\bullet\) Sentences at soft, medium and loud intensity levels \\ \cline{2-6}  & & & & \(\bullet\) Descriptive speech (picture) & \(\bullet\) Reading standard text (\"Rainbow passage\") & \(\bullet\) Parent-child speech (\"Gollolloids and The Three Little Bears\") & \(\bullet\) Thematic speech with emotions (such as sadness or happiness\") & \(\bullet\) Sinting passage (\"Flappy Birthday\") \\ \hline [PERSON], [PERSON], et al. (2001) [7] & \(\bullet\) Recommendations of ELS\({}^{\circ}\) experts and members for technical recording standards and token types for multidimensional functional voice assessment & \(\bullet\) VRP\({}^{\text{d}}\) (highest frequency, softest intensity, and lowest frequency) & \(\bullet\) Digital recording. sampling frequency at least 20–100 kHz & \(\bullet\) [a] \(\bullet\) at comfortable pitch and loudness (3\(\times\)) \\ \cline{2-6}  & Summary of evidence, calls attention for low reliability of acoustic analysis in strongly aperiodic signals & \(\bullet\) Perturbation parameters jitter and shimmer & \(\bullet\) Voice quality measurements: microphone-to-mouth distance of 10 cm, with 45 \({}^{\circ}\) 90 \({}^{\circ}\) angle, VRP measurements with 30 cm distance. & \(\bullet\) Voice quality (a] \(\bullet\) at comfortable pitch and loudness (3\(\times\)) \\ \hline \end{tabular}
\end{table} 
Table 1: Summary of Acoustic Analysis Recommendations and Guidelines.