highest-pitched

Adjective

high-pitched (comparative higher-pitched, superlative highest-pitched)

1. Of a sound, having a high pitch.
   • With a "peep" from a high-pitched whistle, the train would leave by the crossover to the down line, […].1954 March, W. A. Tuplin, “Recollections of the Wirral Railway”, in Railway Magazine, page 168

   Synonyms:

   high, high-pitch, fluty, piping

   Antonyms:

   low, low-pitched

2. Of a steam locomotive boiler, placed higher than usual.
   • The 2-6-2s have very high-pitched boilers in order that the grate shall clear the radial axle and also the trailing coupled wheels.1960 September, P. Ransome-Wallis, “Modern motive power of the German Federal Railway: Part One”, in Trains Illustrated, page 553
3. (dated, figuratively) Haughty.