Built-in speakers

How it tests

Plays 2–5 beeps (700 Hz) on the left channel, then the right, and asks how many; then a spoken word picked from four. A miss gets one retry with a new count or word. Mixer saved, set to fixed levels, restored.

How it decides

Supported: both counts right; the word right too makes it a challenge, a skipped word leaves it observed. Partial: one side silent, or the word missed twice. Failed: nothing heard. Uncertain: a side missed twice with sound on both.

How sure it is

A challenge the tester can't guess. It doesn't judge sound quality, and on Macs with separate woofers it doesn't test them on their own.

On a real Mac

• On a MacBook Air (13-inch, Mid 2012): both speakers, the word picked right.

What could mislead it

• Could pass when it shouldn'tSound is crackly or tinny (woofers silent) but beeps are countable.
• Could end without a verdictA loud room or a hard-of-hearing tester gets uncertain.