Supraglottic Activity in Healthy Classically Trained Singers: A Scoping Review of MRI and Endoscopic Evidence

Supraglottic adjustments observed in classically trained singers frequently resemble patterns associated with clinical hyperfunction, yet their manifestation across singing conditions and their interpretation in healthy artistic voice use remains incompletely characterized. This scoping review aimed to synthesize evidence on supraglottic activity in healthy classically trained singers, identify the conditions under which these behaviors occur, and clarify how they should be interpreted relative to clinical definitions of hyperfunction.

Following the Arksey and O'Malley framework and PRISMA-ScR guidelines, a systematic search was conducted across 10 databases covering publications from 1987 to 2025. Studies were eligible if they examined supraglottic activity in healthy adult classical singers using videolaryngoscopy or magnetic resonance imaging (MRI). Seventeen studies met the inclusion criteria and were synthesized narratively.

Four supraglottic configurations recurred across studies regardless of imaging modality: vertical laryngeal displacement, pharyngeal and epilaryngeal shaping, anterior-posterior (A-P) compression, and medial compression. These behaviors were consistently modulated by pitch, loudness, register, vowel, voice type, sex, and pedagogical concepts. MRI studies documented systematic laryngeal lowering and hypopharyngeal expansion during classical singing, particularly in males, with epilaryngeal narrowing increasing with loudness. Endoscopic studies revealed A-P and medial compression as common findings in healthy singers, with A-P compression predominating and both types increasing at louder dynamics. Sex-related differences were present across modalities, suggesting differing patterns of supraglottic adjustment between male and female singers.

Supraglottic behavior in classically trained singers is highly context-dependent, and the frequent observation of these behaviors in healthy trained voices suggests that they may reflect functional acoustic and physiologic adjustments rather than inherently maladaptive activity. These findings support a context-sensitive interpretation of supraglottic activity in clinical voice assessment, cautioning against pathologizing behaviors that may represent stylistically adaptive technique in trained singers.