The Recorder's Paradox

The need to access vernacular speech styles, which appear in informal, uncontrolled environments poses a problem for the recording of audio high enough in quality for acoustic analysis. As a result, sociolinguistic interviews are either relatively formal and controlled resulting in more formal speech and decent quality audio OR informal, uncontrolled contexts with a decent level of vernacular speech yet low quality audio. This poses a problem for the analysis of vernacular speech. Studies show the effects of noise on voice quality properties but are noisy environments actually detrimental to analysis of formant frequencies? Does noise affect all formants equally? What types of noise should be avoided?