Adjectives

(s)blatant, clamant, clamorous, strident, vociferousconspicuously and offensively loud; given to vehement outcry“blatant radios”, “a clamorous uproar”, “strident demands”, “a vociferous mob”
(s)fricative, continuant, sibilant, spirant, stridentof speech sounds produced by forcing air through a constricted passage (as ‘f’, ‘s’, ‘z’, or ‘th’ in both ‘thin’ and ‘then’)
(s)strident, shrillbeing sharply insistent on being heard“strident demands”, “shrill criticism”
(s)raucous, stridentunpleasantly loud and harsh