You could also do it with a single  s/// substitution, although it is messier and almost certainly slower than a double-tr/// approach:

>perl -wMstrict -le
"my %xlate = qw(t f  h l  i i  s p);
 ;;
 my $s = 'alters';
 $s =~ s{ . }{ $xlate{${^MATCH}} // '' }xmsgpe;
 print qq{'$s'};
"
'fp'
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