votcorpora: VOT production data from various sources

#' @import tibble
NULL

#' Combined VOT production data
#'
#' Word initial VOT measurements from four different production experiments. Two
#' are isolated word reading, one is sentence reading, and one is conversational
#' speech from interviews.
#'
#' The sources are
#' \describe{
#' 
#' \item{bbg09}{Baese-Berk & Goldrick (2009), experiment 1 measured voice onset
#'   time for monosyllabic words with word-initial voiceless stops. Some words
#'   had voiced minimal pair, while others did not. Words were read in isolation
#'   with other monosyllabic fillers that did not have initial stops. Experiment
#'   1a only had /p/-initial words, and Experiment 1b had /t/ and /k/.}
#'
#' \item{gva13}{Goldrick, Vaughn, & Murphy (2013), experiment 1 is analogous to
#'   \code{bbg09} but with voiced stops.}
#'   
#' \item{allen-miller}{Allen & Miller (1999). Experiment 1 was similar to
#'   \code{gva13} and measured VOTs for voiced and voiceless stops in
#'   monosyllabic words from . Experiment 2 was the same as Experiment 1 but
#'   included the additional manipulation of speaking rate (fast and
#'   slow). Prevoiced stops and errors are coded as NA. Since all words were
#'   monosyllabic with a final stop consonant, the stop consonant phoneme is
#'   included (\code{final_phoneme}), as is the measurements of closure and
#'   aspiration duration (\code{final_closure} and \code{final_aspiration}).}
#'
#' \item{levari-sent}{Lev-Ari, S., & Peperkamp, S. (2013). English-French
#'   bilinguals (English L1) read 16 sentences, 10 of which contained one word
#'   each starting with /p/, /t/, and /k/. (Items are the English sentences from
#'   Fowler, Sramkoc, Ostrya, Rowlanda, & Halle, 2008)}
#'
#' \item{levari-convo}{A subset of the talkers from \code{levari-sent} conducted
#'   interviews, from which VOTs of all word-initial voiceless stops were
#'   measured.}
#'
#' \item{buckeye}{Nelson, Noah & Wedel, Andrew (under revision).  The phonetic
#'   specificity of competition: Contrastive hyperarticulation of voice onset
#'   time in conversational English.  VOTs manually extracted from the Buckeye
#'   Corpus of conversational speech by Andy Wedel. Age is coded as old (40+) or
#'   young (under 40).  Includes two measures of local speech rate, syllables
#'   per second and total stop length.}
#'   
#' 
#' }
#' 
#'
#' @format A data frame with 14,262 observations of 12 variables:
#' \describe{
#' \item{source}{The source of this observation}
#' \item{subject}{ID of the talker that produced this observation}
#' \item{phoneme}{Phoneme whose VOT was measured}
#' \item{final_phoneme}{Final phoneme in the word (\code{allen-miller} only; all
#'   voiced/voiceless stops)}
#' \item{vot}{Voice onset time in ms}
#' \item{vowel_duration}{Duration of the following vowel in ms}
#' \item{final_closure}{Closure duration of final stop (\code{allen-miller} only).}
#' \item{final_aspiration}{Duration of release burst of final stop
#'   (\code{allen-miller} only).}
#' \item{prevoiced}{For voiced stops, TRUE if prevoicing was present, FALSE if
#'   not. NA for voiceless stops}
#' \item{word}{Word that the phoneme occurred in}
#' \item{sex}{The sex of the talker ('m' or 'f'), NA if missing (\code{bbg09}).}
#' \item{age}{The age of the talker, NA if missing (\code{bbg09} and
#'   \code{gva13}).}
#' \item{age_group}{The age group of the talker ('o' for over 40, and 'y' for
#'   under 30; based on the Buckeye Corpus scheme).}
#' \item{bilingual}{TRUE for French-English bilinguals, FALSE for english
#'   monolinguals}
#' \item{speech_rate}{The local speech rate (for Buckeye only) in syllables per
#'   second. This is calculated based on the number of vowels in the continuous
#'   speech window around the word where VOT was extracted.}
#' \item{speech_rate_condition}{Allen & Miller (1999) elicited slow and fast
#'   speech rates in their Experiment 2 by varying the instructions and the time
#'   that the word was displayed (1500ms for the "slow" rate, and 750ms for the
#'   "fast" rate)}.
#' \item{stop_length}{The length of the whole stop, from burst to following
#'   sonorant onset (Buckeye only), in ms.}
#' \item{voicing}{Is the phoneme \code{voiced} or \code{voiceless}.}
#' \item{place}{Place of articulation. \code{cor} for coronal, \code{lab} for
#'   labial, and \code{dor} for dorsal.}
#' }
"vot"