FUNCTION AND MORPHOLOGY OF THE LARYNX OF THE DOMESTIC GUINEA-PIG - A LARYNGOLOGIC AND PHONIATRIC MODEL

The present study was undertaken to collect data on fundamental functi onal and morphological features of the guinea pig larynx using frequen cy analysis of animal vocalizations and light and scanning electron mi croscopy. Vocalizations of healthy animals were recorded in an anechoi c chamber and were analyzed with short-time fourier transformation (co lor spectrograms). From the multitude of vocalization patterns produce d by the guinea pig, distress squeals were selected as a typical, repr oducible, voiced sound. These were stereotyped, upward-frequency modul ated, multiharmonic signals with a formant-like structure. The fundame ntal frequency of this sound rose by about 1.5 octaves and reached up to 6 kHz near the end of the call. The different regions of the endola ryngeal epithelia showed morphological properties that corresponded to proposed functional significance. Keratinized squamous epithelium cov ered the supraglottic region. The marginal rim of the vocal cord was c overed by a very thin epithelium with very flat cells covered with sho rt microvilli. The subepithelial space was filled with loose connectiv e tissue. The subglottic region was covered by respiratory epithelia. Based on these findings, we propose that the larynx of the guinea pig can be used as a model in phoniatric and laryngological research.