Human Voice: Production and Study

• Voice is the sound humans and other vertebrates produce, using vocal folds/cords for speaking, singing, laughing, crying, screaming, etc.
• Human voice is the sound made by a human using their vocal cords.
• The voice is used for communication, expression, and singing.
• Voice study includes linguistics, phonetics, physiology, psychology, and music.

Voice Production

• Voice production requires the respiratory, phonatory, and articulatory/resonatory systems.
• Respiration powers the voice
• Inhalation brings air into the lungs; exhalation forces air through the larynx.
• The larynx, or voice box, houses the vocal folds.
• Vocal folds are two bands of smooth muscle tissue that vibrate to create sound.
• Air from the lungs vibrates the vocal folds.
• Vibration frequency determines the pitch of the sound.
• Higher frequency equates to higher pitch, lower frequency to lower pitch.
• Vocal folds abduct (open) during breathing and adduct (close) during phonation.
• Articulation and resonance shape the sound from the vocal folds.
• Articulators: tongue, teeth, lips, palate, and jaw.
• These structures change the sound wave to produce speech sounds.
• Resonance happens as sound travels through the vocal tract (pharynx, oral cavity, nasal cavity).
• Cavity size and shape affects voice timbre/quality.

Voice Characteristics

• Voice characteristics: pitch, loudness, timbre, and resonance.
• Pitch is the perceptual correlate of frequency, indicating how high or low a voice sounds.
• Loudness/intensity is the perceptual correlate of amplitude, indicating the perceived volume.
• Timbre/quality is the unique sound of a voice, from the blend of fundamental frequency and overtones.
• Resonance is the modification of vocal tone as it passes through the vocal tract.
• Different articulation/resonance patterns create different speech sounds or vocal qualities.

Voice Disorders

• Voice disorders affect voice quality, pitch, loudness, or comfort.
• Disorders from vocal misuse/overuse, medical conditions, neurological/psychological factors.
• Common voice disorders: vocal nodules, polyps, laryngitis, vocal fold paralysis, spasmodic dysphonia, muscle tension dysphonia.
• Vocal nodules are benign growths on vocal folds caused by chronic vocal abuse.
• Vocal polyps are similar to nodules, typically larger, and from a single vocal trauma episode.
• Laryngitis is larynx inflammation, often from viral/bacterial infection, or vocal strain.
• Vocal fold paralysis: one or both vocal folds can't move, often due to nerve damage.
• Spasmodic dysphonia: neurological disorder with involuntary vocal fold spasms, resulting in strained voice.
• Muscle tension dysphonia: voice disorder from excessive laryngeal and surrounding muscle tension.

Voice Assessment

• Voice assessment involves vocal function evaluation by a speech-language pathologist or otolaryngologist.
• Assessment: case history, perceptual evaluation, acoustic analysis, aerodynamic measurements, and laryngeal exam.
• Case history: gathering info on patient's medical history, vocal habits, and voice problem.
• Perceptual evaluation: listening to the patient’s voice and rating pitch, loudness, quality, and resonance.
• Acoustic analysis: instruments measure voice parameters such as fundamental frequency, intensity, and spectral characteristics.
• Aerodynamic measurements: assess airflow/pressure with voice production.
• Laryngeal examination: visualizing larynx/vocal folds using laryngoscopy or stroboscopy.

Voice Therapy

• Voice therapy aims to improve vocal function and alleviate voice symptoms using techniques and exercises.
• Therapy conducted by speech-language pathologist specializing in voice disorders.
• Common techniques: vocal hygiene education, resonant voice therapy, semi-occluded vocal tract exercises, and laryngeal massage.
• Vocal hygiene education: teaching healthy vocal habits and strategies to prevent vocal abuse/misuse.
• Resonant voice therapy: optimizing vocal resonance to improve voice quality and reduce vocal effort.
• Semi-occluded vocal tract exercises: sounds through a narrow constriction in the vocal tract to improve vocal fold adduction/resonance.
• Laryngeal massage: manual manipulation of larynx and surrounding muscles to reduce muscle tension and improve vocal function.

Singing Voice

• Singing voice is specialized for musical expression.
• Requires vocal technique, musicality, and artistic interpretation.
• Singing involves precise control of pitch, rhythm, dynamics, and timbre.
• Singers train to develop vocal range, flexibility, and endurance.
• Vocal technique for singing: breath support, vocal resonance, articulation, and vibrato.
• Breath support: using the diaphragm/abdominal muscles to control airflow and maintain consistent vocal tone.
• Vocal resonance: optimizing sound amplification/projection through vocal tract.
• Articulation: clear enunciation of words/lyrics.
• Vibrato: slight, rapid pitch variation for warmth/expressiveness.
• Different singing genres (opera, musical theater, pop, jazz) need different techniques/styles.

Vocal Registers

• Vocal registers are specific series of tones, produced by a particular mode of vibration of the vocal folds.
• Different registers have distinct timbral/acoustic qualities.
• Common registers: modal voice (chest voice), falsetto, and whistle register.
• Modal voice: register for normal speaking/singing, includes full and balanced vocal fold vibration.
• Falsetto: higher register by lengthening/thinning vocal folds, has a breathy tone.
• Whistle register: highest register; vibrates a small portion of vocal folds for a high-pitched, flute-like sound.
• Passaggio is the transition between vocal registers; singers train to smooth these transitions.