A huge variety of speech sounds can be made without vocal folds

Evidence

In spite of its importance, some implications of resonance are often sadly overlooked. For example, the source filter theory of vocalization (see section 17.4) assigns only a passive filtration role to our vocal tract, so that it merely “suppresses the passage of sound energy at certain frequencies while allowing its passage at other frequencies.” In fact, the vocal tract is an active amplifier at some frequencies (the formants), literally coaxing more energy out of the vocal fold air pulsations than without the vocal tract attached. — Eric J. Heller, Why You Hear What You Hear- An…, 883 (#expands, via linked claim)

Categorization

• XREF: connects to: Different voice qualities result from distinct vocal fold modes; Speech production reduces to a source-filter model with glottal or noise sources; The vocal tract actively amplifies speech rather than merely filtering it — Eric J. Heller, Why You Hear What You Hear- An…, 883 (+1 more)

Broader Connections

• Speech production reduces to a source-filter model with glottal or noise sources #corroborates (0.85)
• The vocal tract actively amplifies speech rather than merely filtering it #expands (0.78) — Eric J. Heller, Why You Hear What You Hear- An…, 883