(
A
) SIOP Boston Grade 0. According to the minimum test battery, 4,000 Hz is tested first (denoted “1”) and with hearing threshold ≤ 20 dB HL, 8,000 Hz is tested second (denoted “2). With 8,000 Hz ≤ 20 dB HL, testing is done. (
B
) SIOP Boston Grade 1. According to the minimum test battery, 4,000 Hz is tested first (denoted “1”) and with hearing threshold ≤ 20 dB HL, 8,000 Hz is tested second (denoted “2). With 8,000 Hz > 20 dB HL, 6,000 Hz is tested third (denoted “3”). (
C
) SIOP Boston Grade 2. According to the minimum test battery, 4,000 Hz is tested first (denoted “1”) and with hearing threshold > 20 dB HL, 2,000 Hz is tested second (denoted “2). With 2,000 Hz ≤ 20 dB HL, 3,000 Hz is tested third (denoted “3”). (
D
) SIOP Boston Grade 3. According to the minimum test battery, 4,000 Hz is tested first (denoted “1”) and with hearing threshold > 20 dB HL, 2,000 Hz is tested second (denoted “2). With 2,000 Hz ≤ 20 dB HL, 3,000 Hz is tested third (denoted “3”). (
E
) SIOP Boston Grade 4. According to the minimum test battery, 4,000 Hz is tested first (denoted “1”) and with hearing threshold > 20 dB HL, 2,000 Hz is tested second (denoted “2). With 2,000 Hz > 20 dB HL, 1,000 Hz is tested third (denoted “3”).