Loads and returns the {symbol: name} dictionary stored in the
		data/ipa.tsv file.

def _load_ipa_data(self, ipa_data_path):
		"""
		Loads and returns the {symbol: name} dictionary stored in the
		data/ipa.tsv file.
		"""
		ipa = {}

		try:
			with open(ipa_data_path, newline='') as f:
				reader = csv.reader(f, delimiter='\t')
				for line in reader:
					if len(line) != 2:
						continue

					if line[0] in ipa:
						raise IPADataError('Bad IPA data file')

					ipa[line[0]] = line[1]

		except (IOError, ValueError) as err:
			self.log.error(str(err))
			raise IPADataError('Could not open the IPA data file')

		return ipa